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Full text of "House wiring made easy: a practical guide for the electrician and home owner"



MADE EASY 



A PRACTICAL GUIDE 

FOR THE 

AND 




SEARS,ROEBUCKandCO. 



Foreword 



The use of electricity is ten times greater today than a quarter of a 
century ago. New uses and new types of electrical equipment are 
constantly being brought before the public — all these new uses and 
devices have steadily increased the current load forcing the Power 
Companies into a continuous program of expansion, increasing the 
wire size of the high line feeders so as to be able to provide adequate 
voltage conditions to their customers. Unfortunately, the customer 
in most cases has failed to take this condition into consideration and 
when wiring his house has provided only for his immediate use 
without consideration for the future. 

It is our hope in writing this book that the reader who contemplates 
wiring his home will do so with considerable thought for the future. 

We have tried in this book to give the reader a clear picture of what 
materials are necessary to complete an adequate wiring job and 
have suggested what we believe to be the simplest method of wir- 
ing an existing building. We have eliminated as far as possible all 
technical phrases and references so as not to confuse the mind of 
the person reading this book who may not have had electrical or 
technical education. 



©COPYRIGHT 1939 BY SEARS ROEBUCK AND CO. 



CHAPTER ONE 

HOUSE WIRING MADE EASY 



The purpose of this book is to familiarize you with the 
most common terms concerning* electricity and electrical 
merchandise, and explains the ordinary methods used in 
house and farm wiring. Lengthy, technical discussions 
about electricity are avoided; the simple A H C's which 
should be common knowledge will be elaborated on as fully 
as possible. 

As a preliminary to the chapters to follow on the use 
and application of electrical materials, it is important first 
to become familiar with some of the important facts and 
terms used with electricity. 

ELECTRIC CURRENT 

The electricity with which we commonly deal is a form of 
energy force that may be transferred into heat, light or 
motion — (motion for instance, such as in an electric motor). 
The flow of electricity cannot be seen, for easier understand- 
ing it will be compared with water in some of the explana- 
tions to follow. 

DIRECT CURRENT 

Direct current (D.C.) is a continuous flow of electricity 
in one direction and may be generated in an electric dynamo. 
However, we arc most familiar with it as it comes from a 
storage battery such as is used in an automobile. It is not 
generally used for power and light because it cannot be 
transmitted over great distances economically. Direct current 
may be compared to the steady How of water through a 
pipe. 

ALTERNATING CURRENT 

Alternating current (A.C.) is a flow of electricity that re- 
verses its direction several times a second. The most common 
type in use today is 60 cycle, in which the direction of the 
flow is reversed 120 times every second. Alternating current 
is generally used today because it can be transmitted at 
high voltages over great distances economically, and can 
be transformed to lower voltage for the home by use of 
comparatively inexpensive transformers. The movement of 
alternating current in a wire can be compared with the. 
action of a reciprocating water pump. 

VOLT 

A volt is the unit of pressure in measuring electrical force. 
It can be compared with pounds per square inch in measur- 
ing water pressure. 

AMPERE 

An ampere is the unit used in measuring the rate of flow 
of electricity just as the expression gallons per minute is 
used in measuring the rate of flow of water, 

WATT 

A watt is the unit of porcer representing work that is done 
by a current of one ampere under a pressure of one volt. 
Arjproximately 746 watts equals one horse power. 



KILOWATT 

A kilowatt is the equivalent of 1000 watts. A kilowatt hour 
is 1000 watts of electricity used in one hour's time. Elec- 
tricitv rates are based on kilowatt hours. 



COST OF OPERATING AN APPLIANCE 

All Underwriters' Approved electrical merchandise bears a 
label which gives the wattage or the voltage and amperage 
of the appliance. The apparent wattage, in the latter in- 
stance, can be determined for straight resistance appliances 
such as irons by multiplying the voltage figure given by 
the amperage figure given. An iron, for example, with the 
following information on the name plate: 6 Amperes — 
110 Volts would be a 660- Watt appliance. To arrive at the 
660-Watt figure, it is only necessary to multiply the amper- 
age by the voltage, or 6 x 110, which gives the 660-Watt 
figure. To figure the cost of operating this iron one hour, 
it is first necessary to determine the rate or cost of elec- 
tricity from your power company. Assuming that the cost 
is 6c per kilowatt hour, and since 660 watts is approxi- 
mately two-thirds of a kilowatt hour, it would mean that 
it would cost 4c per hour to operate the electric iron. 

HOW TO READ AN ELECTRIC METER 

Your electric meter has four dials that look much like 
small clock faces. Each dial has a single pointer or hand. 
Read the dials from left to right. 




Write down the figure that the pointer has just passed 
on each of the dials. The reading on the above set of dials 
is 3456 kilowatt hours. Now assume that the above figures 
represent the reading at the first of the month. The first of 
the next month, the dials on your meter appear as follows'. 




Reading them as before, we obtain 3592 kilowatt hours. The 
difference between these two readings is 136 kilowatt hours, 
which is the amount of electricity you consumed during a 
month's time. 

To figure your light bill, you would multiply 136 by your 
electricity rate. At 6c per kilowatt, your bill would be $8.16. 

Page One 



In order to transmit electricity, it must be conducted from 
its place of origin to the place it will be consumed or used 
and then back to its place of origin. That is why two wires 
or conductors are necessary to operate any electrical ap- 
pliance. More than one appliance can be operated from one 
circuit as illustrated below. 



FLOW OF CURRENT 




FLOW OF CURRENT 



FLOW OF CURRENT 






FLOW OF CURRENT 



SWITCH 




A switch is a device used to break a circuit to interrupt the 
flow of electricity. 

Switches are furnished in several types; surface and 
flush mounting; single pole, double pole, three-way and 
four- way toggle and push button operation. Switches can be 
furnished in combination with convenience receptacles, pilot 
lights or several switches can be obtained mounted together 
in one unit. 



RECEPTACLE 







A receptacle is a convenient tap from which an electric cur- 
rent may be obtained by inserting a suitable plug. Recep- 
tacles are usually furnished in the duplex type; however, 
they may be obtained as single or triple units. 

Convenience receptacles are made up in combination 
with switches, pilot lights and radio receptacles. Recep- 
tacles are obtainable in indoor, weather-proof and explo- 
sion-proof types and are made in a number of capacities. 

Page Two 



FUSES 

A fuse is a safety device placed in a circuit. It will blow 
and break the circuit in case of a short or overload. Fuses 
are used to reduce fire hazards just as safety valves arc 
used on steam boilers to prevent an explosion. 

When selecting the types of switches for operation of your 
lights, it is advisable to keep in mind the various types and 
styles available. 

If your room lias but one entrance, a single pole toggle 
or push button switch mounted flush with the wall is ade- 
quate; if, however, your room is large and has more than 
one entrance it is sometimes wiser to install two or more 
switches for control of the same lighting unit. When two 
switches are used to control the same light, whether it be in 
the same room as the light outlet or at some distant point, 
two three-way switches, either toggle or push button opera- 
tion, must be used. If it is desirable to control light unit 
from more than two positions the following must be used: 
two three-way switches, either toggle or push button, and 
one four-way switch for every additional point of control 
desired. 

When a light is to be controlled from some distant point, 
such as light unit in basement, garage, or barn, with switch 
control located in kitchen or some other room, it will be 
found advantageous to install a combination toggle switch 
and pilot light. The pilot light will indicate when lights at 
distant points are burning, preventing needless waste of 
electric current. 

Another method of preventing waste of electric current 
especially in clothes and storage closets and attics, is to 
install an automatic door switch. An automatic door switch 
is placed in a door casing and turns the light unit on when 
door is opened, and off when door is closed; therefore when 
entering or leaving a room with your arms full of pack- 
ages, it is not necessary for you to fumble around in the 
dark trying to locate a wall switch. 

Your profits from the sale of eggs can be increased if 
you will install an automatic unit switch to turn on your 
lights early in the morning (and in winter when it begins 
to get dark in the evening)— thus extending the hours of 
light — giving your chickens more time in which to eat and 
exercise — thereby increasing the egg yield per year. Ex- 
perience has shown that the expense of installing automatic 
time switches and the additional electric current cost has 
been more than offset within a few months by the additional 
egg yield obtained. 

Weatherproof convenience receptacles mounted on the 
outside of your house will permit yard or garden lighting 
during certain seasons of the year, such as Christmas or 
Easter, and ornamental garden lighting in the summer. 
Heavy duty weatherproof power receptacles mounted on the 
outside of barns and other out-buildings will make possible 
the operation of portable feed and ensilage grinders, port- 
able electric saws and many other portable electric power 
machines. 

Vapor-proof convenience receptacles located between 
stalls in your dairy barns facilitate the operation of port- 
able electric milking machines. Other types of receptacles 
may be located in the dairy to operate small churns, cream 
separators, and milk coolers. 

Be sure that all the materials to be installed in your 
home and out-buildings are of high quality and are ap- 
proved by Underwriters' Laboratory, Inc. The Under- 
writers* Laboratory insignia is your protection against 
low quality, dangerous, unapproved wiring materials. 



CHAPTER TWO 

WIRING YOUR HOME 



When considering wiring, both for convenience and safety, 
you must not lose sight of the fact that THE WIRING IN 
YOUR HOME IS ONE OF THE MOST IMPORTANT 
FEATURES IN YOUR HOME. Electricity can be your 
most valuable servant, provided your home is adequately 
wired, and can bring you all the conveniences, comforts 
and economies of modern lighting, modern appliances and 
modern labor saving devices. "Adequate wiring" means, a 
sufficient number of outlets to operate the electric iron, 
kitchen appliances, vacuum cleaner, floor and table lamps 
and many other electrical household necessities of today 
at the point where they are used; a sufficient number of 
switches to conveniently operate the lights in eaeli room; 
large enough electric service into the home; wires large 
enough to safely and economically carry the current to all 
the various appliances and lights — and last but not least, 
plan for the future. Through shortsightedness and poor 
advice many homes wired ten years ago are out of date 
because the conductors cannot carry safely the current re- 
quired by the numerous modern appliances and labor saving 
devices of today. Think of the uses you plan to make of 
electricity immediately and add those uses you think you 
will make in the future — then wire your home accordingly. 

SUGGESTED PLAN AND LAYOUT 

Of first importance in wiring a home is a general plan 
showing where the outlets for fixtures, convenience outlets 
and switches are to be located. To make the plan more 
readable, symbols for the various types of outlets are used 
such as illustrated in lower corner of page. 

The following pages will illustrate and describe a plan 
and layout for the wiring of a seven-room, two-story house. 
It is our intention to use, in this typical case, a home that 
has been standing for a number of years in which electricity 
is to be installed for the first time. It is important to keep 
in mind that outlets, in broad terms, are considered those 
that will be used for some current consuming devices such 
as an electric lighting fixture or convenience outlets used 
to operate appliances. Switches are not outlets, but merely 
a device to control the current flowing through the outlet. 

The outlets are located on circuits, which are simply 
paths for carrying electricity from the entrance service 
switch to the various outlets. The number of circuits to be 
used in a home depends on the number of outlets the home 
owner wishes to install, and the square feet of floor area of 
the building. The National Electric Code limits the number 
of outlets per circuit to 12 with the use of 14 gauge wire, 
with the exception that if one 15-ampere branch circuit is 
installed for each 500 feet of floor space, there is no limit 
to the number of outlets which may be placed on this circuit. 

NUMBER OF CIRCUITS REQUIRED 

To determine the number of circuits needed for adequate 
wiring of a home, the following formula shall be used. 
Take the outside measurement of every finished area to be 
used for habitable purposes, including finished attics, game 
rooms or studies in basement and garages containing more 
than two cars. 

When the total area has been determined it is to be 
multiplied by 2 (which is the minimum wattage required 
per square foot of floor area) ; to this sum must be added 
the total appliance load. Grand wattage total is to be 
divided by the voltage, result then being divided by 15 



(which is the maximum amperage permitted on circuits other 
than appliance circuits). For example, a home having a 
total area of 4500 square feet and an appliance load of 
1500 watts: 

Lighting Load 4500 sq. ft. x 2 9000 watts 

Appliance Load Kitchen 500 watts 

Laundry 500 watts 1500 watts 

Dining Room 500 watts 

Total 10,500 watts 

FOR 115 VOLT SERVICE 

10,500 divided by 115 = 91 amps., or 5-15 amp. and 1-20 
amp. (appliance load) circuits. 

FOR 230 VOLT SERVICE 

10,500 divided by 230 = 48 amps., or ^-15 amp. and 1-20 
amp. (appliance load) circuits. 



Circuit 



Circuit 



Circuit 



Circuit 



No. 1 


-3 


Easement Lights 




2 


Kitchen Lights 




1 


Upper Hall Light 




2 


Bedroom Lights (front) 




if 


Bathroom Lights 


Total 


10 


Outlets 


Xo. 2- 


-4 


Living Room Receptacles 




5 


Bedroom Receptacles (front) 




1 


Bathroom Receptacle 




1 


Lower Hall Light 




1 


Porch Light 


Total 


12 


Outlets 


No. 3- 


2 


Laundry Receptacles 




2 


Kitchen Receptacles 




1 


Dining Room Receptacles 


Total 


8 


Outlets 


Xo. 4- 


-1 


Basement Light 




1 


Dining Room Light 




2 


Bedroom Lights (back) 




4 


Bedroom Receptacles (back) 




8 


Living Room Lights 


Total 


11 


Outlets 



CEILING OUTLET 



WALL OUTLET 



CONVENIENCE C* 

RECEPTACLE / 

(DUPLEX) £> 



JUNCTION BOX 






Page Three 



CHAPTER THREE 

WIRING LAYOUT AND PROCEDURE 

INDEX OF OUTLETS, SWITCHES AND RECEPTACLES 

SYMBOL ITEM LOCATION CIRCUIT NO. 

A Main Switch Basement 

B Combination Switch and Pilot Light. . .Kitchen 1 

C Outlet Basement 1 

D Outlet Basement 1 

E Outlet Basement 1 

F , , , . Outlet Basement 4 

G Single Pole Switch Kitchen 1 

H Outlet Kitchen 1 

J Outlet Kitchen 1 

K . .3-Way Switch Dining Room 4 

L 3-Way Switch . Living Room 4 

\[ Outlet Dining Room 4 

X 3-Way Switch Living Room 4 

R 3-Way Switch Living Room 4 

S Outlet Living Room 4 

T Outlet Living Room Bracket .... 1* 

V . . Outlet Living Room Bracket 4 

W Receptacle . Basement 3 

X Receptacle Basement 3 

Z Receptacle Kitchen 3 

Al Receptacle Kitchen 3 

A2 Receptacle Dining Room .3 

A3 Receptacle Dining Room 3 

A4 Receptacle Dining Room 3 

A5 Receptacle Dining Room 3 

A(3 Receptacle Living Room 2 

A 7 Receptacle Living Room 2 

A8 Receptacle Living Room 



o 



Page Four 



A9 Receptacle Living Room 

Bl 3-Way Switch Lower Hall 2 

B2 Single Pole Switch Lower Hall 2 

B3 Outlet ( Bracket ) Porch 2 

B4 3-Way Switch Lower Hall . . 1 

B5 3-Way Switch Upper Hall 2 

B6 3-Way Switch Upper Hall 1 

B7 Outlet Upper Hall 1 

B8 Single Pole Switch Bedroom No. C 4 

B9 Outlet . Bedroom No, C 4 

Bll Outlet Lower Hall 2 

Cl Single Pole Switch Bedroom No. D 4 

C2 Outlet . Bedroom No. D 4 

C3 Single Pole Switch Bathroom 1 

C4 Outlet Bathroom 1 

C5 Bracket Outlet Bathroom 1 

C(j Single Pole Switch Bedroom No. A. . . 1 

C7 Outlet Bedroom No. A 1 

C8 . . . .Outlet Bedroom No. B 1 

C9 Single Pole Switch Bedroom No. B 1 

Dl Receptacle Bedroom No. A 2 

D2 ........... Receptacle Bedroom No. A 2 

D3 Receptacle Bedroom No. B 2 

D4 Receptacle Bedroom No. B 2 

D5 Receptacle Bedroom No. A . . . . 2 

D6 Receptacle Bathroom 2 

D7 Receptacle Bedroom No. D 4 

DS Receptacle Bedroom No. D 4 

D9 Receptacle Bedroom No. C 4 

El Receptacle . Bedroom No. C 4 




DRAWING No. 6 



Page Five 



\v\\ 



DRAWING No. 7 




Page Six 



L 




DRAWING No. 8 



Page Seven 



r*. 



LOCATION OF OUTLETS 



The location and number of outlets deserves careful thought 
since the greatest satisfaction and utility derived from 
electricity results from a sufficient number of outlets properly 
located. Those we recommend and place in this seven room 
house are installed with this thought in mind. 

BASEMENT PLAN 

SEE DRAWINGS 6 AND 7— Pages 5 and 6 

According to the basement plan and layout, four ceiling 
lights are to be installed. The one at the foot of the stair- 
ease will be controlled by a single switch at the head of 
the stairs on the kitchen side of the door. The lights near 
the furnace, over the laundry tubs and work bench will 
be pull chain and will not be switch operated. Outlets will 
be located alongside of the laundry tub for operation of a 
washer or electric ironer and one will be located at the work 
bench for the operation of small motors or electrically 
driven tools. 

1st FLOOR PLAN 

SEE DRAWING 8 — Page 7 

On this plan of the first floor, there will be one ceiling 
light in the kitchen controlled by a single switch on the 
wall as you enter the kitchen through the hall. There is to 
be a wall bracket type of fixture over the sink, controlled 
by a pull chain, and a convenience outlet over the drain- 
board to operate labor saving kitchen appliances. In the 
right hand corner is to be located another outlet to operate 
an electric refrigerator. It is our intention to have an electric 
range installed on the left hand side of kitchen. It will be 
connected direct to the entrance switch in the basement. 

The dining room ceiling light will be controlled by two 
three-way switches, one located in the living room wall at 
the entrance to the dining room, and the other in the 
kitchen wall at the entrance to the dining room. These 
switches permit the operation of a dining room light from 
two different points. There are to be four convenience out- 
lets to operate a vacuum cleaner or table appliances such 
as toasters, waffle irons, percolators, etc. 

There will be a center ceiling light in the living room con- 
trolled by two three-way switches — one in the wall be- 
tween living room and hall and one in back wall next to 
dining room switch. On either side of the fireplace there 
will be a lighting bracket to match the ceiling fixture. There 
are to be four convenience outlets located in this room to 
operate table and floor lamps and eliminate as far as pos- 
sible unsightly wires from these lamps. 

A ceiling light in the hall will be operated by two three- 
way switches, one downstairs and one at the head of the 
stairs on the second floor. The outdoor light will be eon- 
trolled by a switch in the hall. One three-way switch for 
second floor hall light will be located with the downstairs 
hall and outdoor light switches. In each of the four bed- 
rooms and one bath on the second floor for general illumina- 
tion there will be a ceiling light controlled by -wall switch 
located at entrance to the room. Convenience outlets in each 
of the bedrooms are for use with floor and bed lights and 
personal appliances such as curling irons, vibrator, etc. They 
are also located in such a manner that will permit easy clean- 
ing of each room with a vacuum cleaner. On the right hand 
wall in the bathroom, there will be a bracket type light 
as well as the regular tvpe convenience outlet on the same 
wall. 



The light in the upper hall is to be controlled by a three- 
way switch located at the same points where the switches 
for controlling the downstairs ball lights are located. 

WIRING PROCEDURE 

You will note in the layout for the branch circuit lighting 
in the basement we have greatly exaggerated comparative 
sizes of the outlets for the purpose of making more clear 
the wiring of each. The main switch and branch circuit box 
is located in the lower left hand corner, directly under the 
kitchen, and consists of a three wire circuit to be connected 
direct to the range as well as 1 two wire branch circuits 
that will control the lights and convenience outlets through 
the house. The wiring layout for each of these circuits is 
planned for wiring a home already built and differs slightly 
from recommendations that would be made for wiring a 
new home. The recommendations made for wiring this 
house are based on ease of installation plus economy in the 
use of wiring materials. 

The two wires on circuit Xo. 1 will control the follow- 
ing outlets: 3 basement lights lettered C, D and K, 2 
kitchen lights, 1 upper hall light. 2 front bedroom lights 
and 2 bath lights. You will note on the plan that basement 
light C is controlled by a single pole switch with a pilot 
light indicating when basement light is burning. The wiring 
of circuit No. 1 is as follows; — Two wires from main 
circuit panel lettered "A" are carried up to combination 
pilot light and switch in kitchen lettered "B". A black wire 
from main circuit panel "A" connects to brass terminal 
lettered Bl on left hand side of combination switch and 
pilot light. The insulation of this wire is removed for about 
«^4 inch approximately six inches from end of wire and 
looped around 13-1 terminal. It is then continued on to 
brass terminal B-2. Before connecting to B-2, however, at- 
tach by splicing, figure 7, page 6, two black wires, one to 
go to outlets D and K and the other to kitchen light switch. 
The white wire from box A is attached to nickel plated ter- 
minal of combination pilot light and switch at point X-l 
which is a nickel plated terminal. Before connecting to 
X-l, three white wires are spliced, running to outlets I) 
and E and one to kitchen light switch and the other to 
outlet C. Circuit to outlet C is completed by running black 
wire from brass terminal B-3 on right hand side of switch. 

The black and white wires terminating at outlet D are 
connected to pull chain socket cover receptacle and by 
splicing to another pair of black and white wires in box lo- 
cated in outlet D are carried over and terminated in box 
at outlet E. Remember when splicing to attach black wires 
to black and white wires to white. From point D another 
pair of wires are spliced and carried up to outlet box C-7 
in ceiling of right front bedroom. The basement light let- 
tered F is placed on circuit No. 1 so that in the event a 
fuse on circuit No. ] is blown, the basement will not be 
in total darkness. Circuit No. h also controls 1 dining room 
light. 2 back bedroom lights, h back bedroom convenience 
receptacles and 3 living room lights. From circuit box A. 
2 wires, one black and one white are run to and termi- 
nate on pull chain receptacle located in outlet box F. 

Two pairs of wires are spliced in box F to wires originat- 
ing in box A before they are connected to pull chain re- 
ceptacle at box F. One pair, black and white wires, con- 
tinue from point F up to dining room switch point K, the 
other paii* to living room switch No. N. 



Page Eight 







DRAWING No. 9 



Page Nine 



BASEMENT KITCHEN, DINING ROOM 
RECEPTACLES 

SEE DRAWING 9 — Page 9 

The basement receptacles will be placed on circuit No. 3 
which also controls 2 convenience receptacles in the kitchen 
and 4« convenience receptacles in the dining room, and must 
be wired with No. 12 wire or larger. This circuit will be 
fused at 20 amperes because of the greater load which may 
be imposed upon it. There are no lighting outlets on this 
circuit nor convenience receptacles in any other rooms. 
Under the new National Electrical Code, it is required that 
all receptacles in the laundry, kitchen, dining room and 
breakfast room be protected independently of any other 
outlet in the home. 

The wiring of basement outlets shall be as follows: 2 
wires, one black and one white are run to outlet W in base- 
ment from circuit box A and connected directly to the'brass 
and nickel contacts on the receptacles. Black wire to brass 
terminal — white wire to nickel terminal. Two other black 
and white wires are connected to the other pair of contacts 
on receptacle — black to brass, white to nickel and at- 
tached directly to the contact points on receptacle at loca- 
tion X. In circuit box A a black and white wire are spliced 
—black to black, white to white, to 2 wires leading to 
receptacle W. These two additional wires are run directly 
to receptacle outlet Z in kitchen and attached, black wire 
to brass, white wire to nickel contact points. Receptacle 
Z is connected to receptacle A-l by 2 wires, black and 
white, connected on the remaining 2 contacts on receptacle 
Z to those on receptacle A-l, black to brass, white to nickel. 
Two more wires connect A-l with receptacle A-2 in the 
dining room. From point A-2, connect receptacle A-3 by 
black wire connected to brass terminals on both receptacles, 
white wire connected to nickel terminals on both receptacles. 
From A-2 a line must be run to supply current to re- 
ceptacles A-4 and A-5. The procedure shall be as follows: 
(see drawing No. 0). A black wire is spliced to black 
wire from receptacle A-l and the white wire is spliced in 
receptacle box A-2 to the white wire from receptacle box 
A-l. These two wires are then run to receptacle A-4 and 
connected, black wire to 1 brass terminal of A-<1, white 
wire to 1 nickel terminal of A-4. Another black wire is 
then connected to other brass terminal of A-4 and one brass 
terminal of A-5. A second white wire is connected to the 
remaining nickel terminal of A-4 and at A-5. 

THE WIRING OF KITCHEN LIGHTS 

SEE DRAWING 11 — Page 12 

As indicated on illustration No. 4 showing wiring of base- 
ment light, 2 wires lead from switch and pilot combination 
No. B to switch controlling kitchen lights (point No. G in 
drawing). The black wire, before being attached to brass 
terminal at G is spliced to another black wire that leads 
to the second floor hall lights. A second wire, red in color, 
and forming 1 of 3 wires leading to outlet H is also spliced 
to this wire. The white wire from pilot switch goes to box 
in which switch No. G is located but does not connect to 
switch. It is spliced to another white wire which goes to 
second floor hall lights and then spliced in box G to white 
wire from outlet H. The other terminal on switch G is con- 
nected to outlet H by a black wire. In reality, there arc 
three wires running from switch G to outlet H. In box of 
outlet H the black wire from switch G terminates at connec- 
tion to fixture. The red wire does not connect to fixture but is 
spliced to a black wire running to outlet J. White wire 
of fixture and white wire running to outlet J are spliced 
to white wire from switch box G. At outlet J, the black 
and white wires are joined with those leading to the fixture. 

Page Ten 



WIRING DINING ROOM 

SEE DRAWING 10 — Page 11 

From outlet F (see drawing of basement wiring) black and 
white wires lead up to box of switch K (see drawing No. 10 
of dining room fixture wiring). The black wire from outlet 
box F is spliced at "K" to a red wire leading to outlet M 
and then connected to bronze terminal of 3-way switch K. 
The white wire from basement is spliced to another white 
wire leading to outlet M. From 2 brass terminals of switch 
"K" 1 red and 1 white wire run to 2 brass terminals at 
switch "L" located in living room wall next to 3-way 
switch No. N controlling living room lights. Attached to 
bronze terminal of switch "L" is a black wire running to 
box of switch "K" and there spliced to black wire which 
is connected to wire from fixture "M". The other wire from 
fixture "M" is connected to white wire from box of switch 
K which is again spliced to white wire leading from box 
of outlet M to switch E-l of right back bedroom. The red 
wire from point K to outlet M is not connected to fixture 
but simply spliced to black wire leading to switch E-l of 
right back bedroom. 



WIRING LIVING ROOM AND HALLWAY 

SEE DRAWINGS 12 — Pages 12 and 13 

From outlet F (see drawing No. 12 basement wiring) black 
and white wires lead up to box of switch N located next to 
switch L (see drawing Nos. 12 and 14). This also is a 
3-way switch allowing control of lights from two different 
points. The black wire is spliced to the black wire leading 
to wall brackets No. T & V and then connected to bronze 
terminal on switch N. The white wire from outlet "F" is 
spliced in box of switch N to 2 other white wires— one 
leading with black wire to wallbrackets — the other to 
switch box of switch R where it is again spliced to white 
wire and run to outlet "S" and there it is connected to 
white wire of fixture. The 2 brass contacts on switch L 
are connected with one red wire and one black wire to 
the two brass terminals on switch R. From the bronze 
terminal on switch R a black wire is run and connected 
to black wire of fixture at outlet S. Note black and white 
wires from box of switch N are carried over to light 
brackets T and V. In box of bracket T black and white 
wires are spliced and carried to bracket V before they 
are connected to wires leading from light bracket at T. 

The control of four living room eonvenience receptacles 
is placed on circuit No. 2 as are the 5 front bedroom con- 
venience receptacles, one bath convenience receptacle, one 
lower hall light and one porch light. All receptacles must, 
under ruling of National Electrical Code, be mounted 
in a wall surface and not in either floor or baseboard unless 
special types of receptacles are used. Special types will 
not be considered here as use of them is usually limited 
to commercial or industrial installation. 

The wiring of circuit No. 2 is as follows: — 2 wires 
from circuit box "A" are carried up through inside of living 
room wall adjacent to hall and connected to convenience 
receptacle A- 6 in left wall of living room. The black wire 
from circuit box "A" is connected to one brass terminal 
in receptacle box A-6, white wire being connected to one 
nickel plated terminal. Two wires running from other two 
terminals of same receptacle are carried to convenience 
receptacle A-7 in back living room wall. Connections are 
made to the receptacle (see drawing No. 13). From re- 
ceptacle A-7j 2 wires are then carried across the room to 
front wall and connected to terminals of convenience re- 
ceptacle A-8 (see drawing No. 13). Two wires from recep- 
tacle A-7 are connected as follows: 



T0 3-WAY SWITCH 
NO. "R" 



DINING ROOM 



TO BEDROOM 

SWITCH 

no. "cr* 




DRAWING No. 10 



<s 



-<s <S> 



r*® <S> J 



®— 



'N' 



TO LIVING ROOM 
BRACKETS NOS, "T" 4. "V" 




TO OUTLET "F" 



: 



1 



p-O 



G>r- J 



TO OUTLET "F" 



Pace Eleven 



^ 



-^* TO "B" 



r 




DRAWING No. 11 




KITCHEN 





LIVING ROOM 



I — <Z> 



>>, 



'N' 



™ 



\l 




DRAWING No. 12 



Pack Twk lve 



w^^^^^^^^^^^^^m t 



TO RECEPTACLE 

-<-NO. "D1" 







DRAWING No. 14 



Pack Tiiiutkkx 




DRAWING No. 13 




UPPER HALL 




TO SWITCH BOX NO. "G" 

DRAWING No. 13A 




BLACK 



RED 

' wTTite" 



Page Fourteen 



J t 



! 



-0 



'BT 







'B2' 



LOWER HALL 
DRAWING No. 14A 





DRAWING No. 15 



ABOVE ILLUSTRATIONS SHOW INSTALLATION 
OF THREE GANG SWITCH UNIT IN LOWER HALL 



Black wire from receptacle A-7 is connected to one brass 
terminal of receptacle A-S. White wire from receptacle 
A-7 is connected to one nickel plated terminal of receptacle 
A-8. Two additional wires are connected, black to brass 
terminal, white to nickel terminal of receptacle A-9 in left 
wall of living room and connected black to brass, white 
to nickel of A-8. Two wires, black to brass, white to nickel, 
are then run from receptacle A-9 to switch box in hall as 
shown in drawing No. 10, and are connected to 3-way 
switch B-l for controlling lower hall light and single 
pole switch B-2 for controlling jmrch light B-3 as shown 
in drawing No. 10. Black wire from receptacle A-9 is 
connected to bronze terminal of 3-way switch B-l and 
looped to one brass terminal of single pole switch B-2. A 
black wire running to porch bracket outlet B-3 is con- 
nected to other brass terminal of single pole switch B-2 
and to one wire of porch bracket in outlet box B-3. White 
wire from receptacle A-9 is spliced in switch box B-l to 
a white wire running to porch bracket outlet B-3 and to 
a white wire running to lower hall ceiling outlet B-ll. A 
red and white wire are connected between the terminals 
of 3-way switch B-l in lower hall and 3-way switch B-5 in 
upper hall. A black wire is then connected to bronze ter- 
minal of 3-way switch B-5 in upper hall and returned to 
switch box B-l in lower hall and there connected to a black 
wire leading to ceiling outlet box B-ll in lower hall. (See 
drawings No. 14, page 13.) 



Two additional wires as noted in drawing No. 14 run 
from convenience receptacle A-8 in front living room wall 
up through outside wall to convenience receptacle D-l lo- 
cated in wall surface of front bedroom No. A. These wires 
are spliced as follows: black wire to receptacle D-l is 
spliced to black wire from receptacle A-7 before it is con- 
nected to brass terminal of receptacle A-8. White wire to 
convenience receptacle D-l is spliced in receptacle box A-8 
to white wire from receptacle A-7 before it is connected to 
nickel plated terminal of receptacle A-8. 

Two wires are connected, black to brass, white to nickel, in 
receptacle box D-l and are carried overhead to left wall of 
bedroom A and there dropped to convenience receptacle 
D-2 and connected, black to brass, and white to nickel. A 
short run is then made between this receptacle and recep- 
tacle D-3 in wall of bedroom B. Another line is connected 
to receptacle D-3, black to brass, white to nickel and may 
be carried overhead and dropped to receptacle D-4 in back 
wall of bedroom B. 

From receptacle A-7 in living room a 2 wire line is 
spliced black to black and white to white then run to re- 
ceptacle D-5 in back wall of bedroom A. A short run is 
then made between receptacle D-5 in back wall of bedroom 
A to receptacle D-6 located in bedroom wall surface- 
maintaining our black to brass— and white to nickel se- 
quence. 

"Pack Fifteen 



LIGHTING OF FRONT BEDROOMS 
A & B AND BATHROOM 

SEE DRAWINGS Nos. 16 AND 18— Pages 17 and 18 

Two wires are spliced to wires in outlet box D in base- 
ment, black to black, and white to white and are then run 
up through outside wall to above second floor ceiling and 
into outlet box C-7 in ceiling of bedroom A. Black wire 
from D is spliced in outlet box C-7 to black wire running 
to bathroom outlet box C-5, to black wire leading to outlet 
box C-8 in ceiling of bedroom B and to black wire leading 
to switch box C-6 in bedroom A. No further connections 
are to be made to this wire, therefore, it will be necessary to 
solder and tape this splice. White wire from outlet box D 
is spliced in outlet box C-7 to a white wire leading to bath- 
room wall outlet C-5, one white wire leading to outlet box 
C-8 in ceiling of bedroom B and one lead of fixture at- 
tached to outlet box C-7 in bedroom A. Black wire from 
C-7 to switch box C-6 in wall of bedroom A is connected 
to one terminal of switch in switch box C-6. White wire in 
box C-6 after having white coating scraped oil" is con- 
nected to other terminal of switch in box C-6. It then runs 
back to outlet box C-7, and after white coating is removed, 
is connected to other lead of fixture mounted on outlet box 
C-7 in bedroom A. In outlet box C-8 of bedroom B black 
wire from outlet C-7 is spliced to black wire leading to 
switch box C-9 and is then soldered and taped in outlet 
box C-8. In switch box C-7, black wire is connected to one 
terminal of single pole switch and the white wire after 
having the white coating scraped is connected to other 
terminal of switch in box C-9. It is then run to outlet in 
box C-8 and after white coating is removed, it is connected 
to one lead of fixture installed on outlet box C-8 to other 
lead of fixture mounted on outlet box C-8. 

In wall outlet box C-5 of bathroom, two wires from out- 
let C-7 are spliced to two wires leading to bathroom ceiling 
outlet C-4, black wire to black, white to white, are then 
connected to leads of bracket fixture mounted on outlet 
C-5. In ceiling outlet C-4, black wire from outlet C-5 is 
connected to a black wire and run to switch box C-3 and 
there connected to one terminal of single pole switch. The 
white wire after having the white coating scraped off is con- 
nected to other terminal of single pole switch and run back 
to ceiling outlet C-4. There, after the white coating is 
removed, is connected to one lead of fixture mounted on 
outlet C-4. White wire from outlet C-5 is connected in outlet 
C-4 to other lead of fixture mounted on outlet C-4. 

THE WIRING OF BACK BEDROOMS 

SEE DRAWINGS Nos. 16 AND 17— Pages 17 and 18 

It will be remembered that from outlet box M in dining 
room a two wire line has been run to switch box C-l in 
back bedroom D. Before black wire from outlet box M is 
connected to switch in box C-l, 2 black wires shall be 
spliced to it. These two black wires are then run. one. to 
receptacle D-7 in back bedroom D, the other shall be run 
to switch box B-8 in back bedroom "C." The black wire 
from outlet box M is then connected to one brass terminal 
of single pole switch C-l. The white wire from outlet box 
M is spliced to 3 white wires in switch box C-l. One white 
wire will run to switch box B-8 in back bedroom C — the 
other white wire will run to receptacle box D-7 in back 



bedroom D and connected to one nickel terminal of re- 
ceptacle D-7— the third white wire running from switch 
box C-l to outlet Box C-2 in back bedroom D, there con- 
nected to one wire of fixture mounted on outlet box C-2. The 
circuit to outlet C-2 is completed when a black wire con- 
nected to remaining fixture lead at outlet box C-2 is con- 
nected to remaining terminal of switch in box C-l. In 
outlet box D-7 a 2 wire line is connected to the re- 
maining two terminals of D-7, black to brass, white to 
nickel, and run across room to another wall of bedroom 
D-7, there connected to a convenience receptacle D-8. black 
to brass, white to nickel. 

In switch box B-8, before any connections are made to 
switch, it will be necessary to splice a black wire to black 
wire from switch box C-l, and then complete the run of 
black wire to convenience receptacle D-9 and there con- 
nected to one brass terminal of receptacle D-9. White wire 
from switch C-l is connected by splice in switch box B-8 
to 2 other white wires, one running to receptacle D-9 in 
wall of bedroom C, being connected to one nickel terminal 
at that point. The other white wire is run from switch B-8 
to ceiling box B-9 in bedroom C. The black wire from Switch 
C-l is then connected to one brass terminal of single pole 
switch located at B-8. Another black wire is connected to 
remaining terminal of B-8 and carried overhead to outlet 
B-9 in ceiling of bedroom C. A two wire line is run be- 
tween receptacle D-9 and receptacle E-l in bedroom C, 
connections being black to brass, white to nickel in both 
receptacles. 

It is required by the code that No. 12 wire be used on 
circuit No. 3 because of the larger current consuming de- 
vices to be used on the convenience outlets and the fact 
that fusing will be 20 amperes. However, it is recom- 
mended that the wire size of the balance of the circuits also 
be No. 12 because of the greater number of lamps being 
used in the well lighted homes of today. As noted in the 
first pages of this book, too small wires only restricts the 
flow of current and adds to the cost of operation to say 
nothing of speeding up the deterioration of the insulation 
of your wires. 

WIRING OF 3-WAY SWITCH 
IN UPPER HALL 

SEE DRAWINGS Nos. 13A— Page 14 

From switch box G in kitchen wall, two wires run up to 
switch box B-6 located at top of stairs in upper hall and 
then connected as follows: 

Black wire from switch box G is connected to bronze ter- 
minal of 8-way switch in switch box B-6* ; white wire from 
switch box G is spliced to white wire running to outlet 
B-7 in upper hall ceiling. A 3- wire line is run from switch 
box B-6 in upper hall to switch box B-4 in lower hall 
and connected thus: red and white wires of 3 wire cable 
are connected to two brass terminals of 8-way switch in 
box B-6 and to two brass terminals of 8-way switch in box 
B-l, black wire in 3 wire cable is connected in switch box 
B-4< to bronze terminal of 8-way switch and back in switch 
box B-6 is connected to a black wire running to ceiling 
outlet B-7. In ceiling outlet B-7, black wire is connected 
to one lead of fixture mounted on outlet B-7 wire. White 
wire from B-6 is connected to other lead of fixture at B-7. 



Pace Sixteen 




DRAWING No. 16 



Page Seventeen 




'D7' 




r-<S> 



% 



'CT 



BEDROOM 





2^^ 



I 



7V 



I 




BEDROOM 
'B' 




a 



V////////////////AW/V , 



Page Eighteen 



DRAWING No. 18 



CHAPTER FOUR 

TYPES OF WIRING 



INDOOR WIRING 

Coincident with the location and wiring of each outlet, a 
decision must be made on the type of wiring that should 
be used. There are three principal types of wiring used in 
house wiring — electrical conduit, both rigid and thin wall, 
cable of the armored or non-metallic sheathed types, and 
knob and tube, which is open wiring with ordinary house 
wire supported by porcelain fittings, each wire being run 
separately and in many cases supported by a separate 
insulator. Each of these types of wiring has its own cer- 
tain advantages, depending in part on the nature of the 
building to be wired, what the building is to be used for 
and whether an installation is being made on a new structure 
or the rewiring of an old one. They are as follows — , 

RIGID OR THIN WALL CONDUIT 

This is probably the safest form of wiring to use under 
ordinary conditions. Rigid and thin wall conduit are both 
made of high grade steel and heavily coated with a rust- 
proof finish. The conduit is j^laced according to the location 
of the outlets and electrical current is carried through 
rubber covered wires drawn through the conduit. This gives 
a waterproof protection to the wires and protects them 
against mechanical injury. High material and installation 
cost limit the use of this form of wiring in rewiring or 
installing wiring in a structure already completed. Certain 
criticism also is placed against the use of conduit in barns 
because of the corrosive effect of the acid fumes on the 
metal, and some local or state codes demand the use of 
non-metallic system in these locations. 




ARMORED OR NON-METALLIC 
SHEATHED CARLE 

Cable either armored or non-metallic sheathed consists of 
two or more rubber covered wires encased in a steel or 
non-metallic cover. Either type is very flexible and easy 
to install but because they are not watertight their use is 
limited to indoor installations only. They are most com- 
monly used in house wiring, both old and hew work, be- 
cause of comparatively low cost and ease of installation. 



INSTALLATION OF RIGID CONDUIT 

The restrictions in the National Electric Code, generally. 
are less on electrical rigid conduit than on any other form 
of electrical wiring. The heavy steel wall prevents damage 
to the wires. Under normal atmospheric conditions the 
conduit is practically rustproof, thereby protecting the 
wires from moisture. It therefore can be run indoors or 
outdoors — overhead or underground. 

Two types of protective coatings are given to conduit. 
A black enameled substance that is baked onto the metal 
or a galvanized finish that is placed on the conduit in a 
molten state, or placed there by an electrolytic process. 
Because it has proven more enduring and rust resistant, a 
majority of engineers and contractors favor the galvanized 
finish even though it is slightly more expensive. 

Rigid conduit can be bent, although it is more practical 
on larger sizes in particular, to use Conduit Ells that are 
already bent (see drawings No. 19) and shaped for imme- 
diate use. All sizes of electrical conduit are supplied in 
standard lengths of 10 feet each electrical trade size, and 
for runs over 10 feet successive lengths of conduit arc 
joined together with conduit couplings. Surface installa- 
tions of rigid conduit are comparatively easy, particularly 
if there are few bends to make. 

Rigid metal conduit may be used under any and all con- 
ditions subject to the following restrictions. 

If conduit is exposed to corrosive fumes or vapors such 
as may exist in fertilizer rooms, hide cellars, salt storages, 
casing rooms and similar locations, conduit and fittings of 
corrosion-resistant material suitable for the conditions 
shall be used. 

Conduit, unless of corrosion-resistant material suitable 
for the purpose, shall not be used in or under cinder fill 
where subject to permanent moisture unless protected on 
all sides by a layer of non-cinder concrete at least two 
inches thick or unless the conduit is at least 18 inches 
under the fill. In portions of dairies, laundries, canneries 
and other locations where excessive moisture is continuously 
or frequently present, and in other locations where walls 
are frequently washed, the entire conduit system, including 
all boxes and fittings used shall be made watertight. 

All ends of conduit shall be reamed to remove rough 
edges. Where a conduit enters a box or other fitting, a 
bushing shall be provided to protect the wire from abrasion 
unless the design of the box or fitting is such as to afford 
equivalent protection. 



LOCKNUT 




DRAWING No. 19 



Page Nineteen 






0> 





WIRING WITH RIGID CONDUIT 

As you will note here the conduit lias been secured to the beams with 
pipe straps and the threaded end placed into the box knockout. It is 
necessary before conduit enters box to place a locknut on the threaded 
end of conduit. After threaded end is inserted in box, the bushing is 
inserted over end of thread and brought up securely. The locknut on 
the outside of box is then backed up tightly against the sides of the 
box so that a completed fastening of the box has been made. The wires 
are then pulled through the conduit, completing the installation. The 
number and size of wires permitted in each size conduit are given in 
Table A — page 46. The use of rigid conduit for service entrance as 
shown in drawing No. 44», page 35 is standard. 

Rigid metal conduit is nominally furnished in trade size of from l/o 
inch internal diameter to 6 inches internal diameter. 

Since some thought must be given to the increased weight of the 
building and additional stress placed upon the supporting members 
when a building is wired with rigid conduit, the table below is given 
for your convenience in calculating the total additional stress the sup- 
porting beams of your building will have to carry. 



Trade 
Size, 
Inches 



Length 



Nominal 
Weight, 
Pounds 

per Foot 



9'llVi" 
9 1 1 W 

9'ir 

9'11" 

9 11" 

9'10!/ 2 " 
9M0V2" 
9'10" 

9M0" 

9'10" 

/ 9 " 

9'9" 



0.852 
1.134 
1.684 

2.281 
2.731 
3.678 

5.819 
7.616 
9.202 

10.889 
12.642 
14.810 

19.185 



External 
Diam- 
eter, 
Inches 



Nominal 
Internal 

Diam- 
eter, 

Inches 



0.840 
1.050 
1.315 

1.660 
1.900 
2.375 

2.875 

3.500 
4.000 

4.500 
5.000 
5.563 

6.625 



0.622 
0.824 
1.049 

1.380 
1.610 
2.067 

2.469 
3.068 
3,548 

4.026 

4.506 
5.047 



Nomina 
Wall 

Thickness 
Inches 



0.109 
0.113 
0.133 

0.140 
0.145 
0.154 

0.203 
0.216 
0.226 

0.237 
0.247 
0.258 



Minimum 
Weight 

10 
Lengths, 
Pounds 



Threads 
per 
Inch 



6.065 0,280 



79 
105 
153 

201 
249 

334 

527 
690 
831 

982 
1,150 
1,344 

1,770 



14 
14 
11 Vi 

\\Vi 

111/2 

8 



Page Twenty 






Q) 



Q 



J 



® 







BLANK METAL COVER 



3-HOLE 

PORCELAIN 

COVER 




EDISON 

BASE 

RECEPTACLE 




DRAWING No. 21 



CONDUIT FITTINGS AND COVERS 



The above illustration shows conduit fittings used for sur- 
face wiring. They are used in conjunction with cither rigid 
or thin wall conduit and can be furnished in a number of 
types and sizes. The five most common types of fittings and 
three most commonly used covers are shown above. They 
are sometimes used as part of conduit runs when a change 
of direction, attachment of a branch run, installation of a 
receptacle or drop cord is desired. 

We will consider these fittings in the order in which they 
are illustrated above. 

First the type "T" fitting is used to provide a connection 
between a continuous conduit run and a right angle branch 
run. The conduit fitting may then be covered with a blank 
plate if no other tap to the wires is needed; the three hole 
cover may be used either as a drop cord cover when it is 
necessary to install a drop light or receptacle to a conduit 
run, or it may be used to connect one, two or three open 
wires to a conduit run; the receptacle is attached to the 
fitting when a lighting unit directly attached to the con- 
duit is desired. It is so designed that a shade holder may be 
clamped directly to the neck of the porcelain socket housing. 

The type "C" fitting is used whenever it is necessary 
to attach a light to the conduit run, or when a connection 
to open wires or the installation of a drop cord is required. 

The type "LB" fitting is used when it is necessary to 
change the direction of a conduit run. Usually used when 



a conduit run is carried along one side of a wall surface 
to a point where it is necessary to change the direction 
of the run by piercing the wall at right angles to the wall 
surface. When used for no other purpose fitting is cov- 
ered with a blank plate, however, the three hole or recep- 
tacle covers may be attached if required. The type "LR" 
fitting is used to make a right angle change of direction 
in a conduit run when both runs are to travel along the 
same wall face. It may be covered in the same manner as 
the type "LB" fitting. 

The type "E" fitting is to be used at the end of a con- 
duit run either for the attachment of a device or as a dead 
end to conduit run. When used as a dead end fitting, 
it is to be covered with a blank cover, however, either the 
three hole cover or the receptacle cover may be used. 

Special fittings somewhat larger than these illustrated 
containing switches for the control of lights can be ob- 
tained. Fittings of various types are used for outdoor 
runs of conduit whenever the installation of weather-proof 
devices is required. They are usually much longer and 
heavier than the fittings illustrated on this page. 

Special fittings are required by the code when con- 
duit runs are installed in permanently moist locations, such 
as steam chambers, etc., where fittings must be vapor-proof, 
and rooms containing explosive vapors, such as gasoline 
refineries where explosion-proof fittings must be used. 

Page Twexty-one 



WIRING WITH THIN WALL CONDUIT 



Although the restrictions placed on the use of thin wall 
conduit by the National Code are more numerous than 
on rigid conduit, for purposes at least of ordinary resi- 
dential and barn wiring, they are not any greater. One 
great distinction between the two types is the difference in 
thickness of the wall of the conduits with a corresponding 
difference in their weight. Thin Wall Conduit is consider- 
ably lighter and the thickness of the wall is not sufficient 
to safely have threads cut on it. For this reason, thin wall 
conduit is connected to boxes and fittings by threadless 
type couplings and connectors that clamp on to the outside 
wall of the conduit. See drawings below. 

Thin wall conduit is supplied in standard 10-foot lengths 
manufactured in a galvanized finish only and is cut and 
bent in the same manner as rigid conduit. Ordinary in- 
stallations rarely require the use of manufactured elbows as 
the smaller wall thickness permits easier bending. 

INSTALLATION OF THIN WALL CONDUIT 

SEE DRAWING No. 23 — Page 23 

Shall comply with the following provisions: It may be 
used for both exposed and concealed work, but not where 
it will be subject to severe mechanical injury; such as in 
cinder concrete or fill unless protected on all sides by a 
layer of non-cinder concrete at least two inches thick, or 
unless the tubing is at least 18 inches under the fill; in 
any hazardous locations, in hoist ways, or where exposed 
to corrosive vapor, except if tubing is exposed to corrosive 
fumes or vapors such as may exist in some fertilizer rooms, 
hide cellars, salt storages, casing rooms and similar loca- 
tions, tubing and fittings of corrosion-resistant material 
suitable for the conditions shall be used. 

In portions of dairies, laundries, canneries and other 
locations where excessive moisture is continuously or fre- 
quently present, and in other locations where walls are 
frequently washed, the entire tubing system, including all 
boxes and fittings used therewith shall be made watertight. 
Tubing 'shall not be coupled together nor connected to 
boxes, fittings or cabinets by means of threads in the wall 
of the tubing. 



Threadless couplings and connectors used with tubing 
shall be made up tight and shall be of the watertight type 
if buried in masonry, concrete or fill, or if installed in wet 
places. 

Bends in tubing shall be so made that the tubing will 
not be injured and that the internal diameter of the tubing- 
will not be reduced. 

The illustration on the following page is a thin wall con- 
duit installation in combination with an outlet box. Note 
the straps used in securing conduit to beams and closeup 
views of connection to box. Here the threadless connector 
is securely fitted over the conduit and securely clamped in 
place. The threaded end of connector has been placed 
through the box knockout and secured to the box by a 
locknut inside the box and over the threaded end of the 
connector. After runs have been made, wires may then be 
easily pulled through conduit and into box. 

The number and size wires permitted in each size con- 
duit are given in Table "A," page 46. 

In using thin wall conduit for service entrance, it is 
necessary to use an Adapter for fastening thin wall con- 
duit to standard service entrance fittings. This adapter 
clamps on to the conduit and its threaded ends are drawn 
up into the standard fittings and clamps itself securely to 
the surface of the conduit. Straps should be used to support 
conduit every 4 feet. 

Chart Showing Actual Weight and Diameter 
of Thin Wall Conduit 



Size, 
Inches 


Approximate Weight 
per 1,000 ft., pounds 


Diameter, Inches 


Internal 


External 


Vb 

Vi 

Va 

1 

P/4 

Wi 

2 


254 
321 
488 
711 
985 
1141 
1470 


0.493 
0.622 
0.824 
1.049 
1.380 
1.610 
2.067 


0.577 
0.706 
0.922 
1.163 
1.508 
1.738 
2.195 




COUPLING 



DRAWING No. 22 



Page T wk:n ty-two 

L 




Page Twenty-three 




DRAWING No. 24 



ARMORED CARLE WIRING 

Armored cable is one of the most widely used materials 
for house wiring both on new and old work chiefly because 
of its comparative low cost, ease in handling, low installa- 
tion cost and adaptability of particular forms of wiring (see 
drawing No. 13). As illustrated, you will note that it con- 
sists of two or more rubber covered wires running parallel 
to each other around which is wound a galvanized steel 
protective strip. Between the wires and the strip a moisture- 
proof paper wrapper is placed (known as Kraft paper). 

Armored cable is not waterproof and its use according 
to the Code must be confined to use indoors. Because it 
affords less mechanical protection to the wires than rigid 
or thin wall conduit, restrictions on its use are more numer- 
ous. Generally speaking, armored cable is suitable for use 
indoors on both exposed and concealed work providing there 
is not an excessive amount of moisture or humidity. 

Installations of armored cable should comply with the 
following provisions: It may be used for both exposed 
work and concealed work in dry locations ; for under plaster 
extensions and embedded in plaster finish on brick or other 
masonry, except where subject to excessive humidity or 
moisture. Armored cable shall contain lead covered con- 
ductors, type ACL, if used where exposed to the weather 
or to continuous moisture, for underground runs and em- 
bedded in masonry, concrete or fill, in buildings in course 
of construction and where exposed to oil, gasoline or other 
materials having a deteriorating effect on rubber. 

The above illustration shows the method of attaching the 
cable to an outlet box. The cable connector lias been slipped 
over the end of the cable and fibre bushing and is secured 
by tightening up on the screw of the connector. The 



threaded end of the connector is inserted into the box knock- 
out and tightly secured by the connector locknut on the in- 
side of the box. 

INSTALLATION OF ARMORED CARLE 

Because the steel strip is spirally wound around the wires, 
it is possible to easily remove this strip if we cut at angles 
as shown on illustration above. Taking an ordinary hack saw, 
simply place the blade on the cable as illustrated and par- 
tially cut through but one section of the armor only. Be 
sure not to cut the wires. Grasp the cable in both hands 
on either side of the cut portion and twist sharply. This 
will break the remaining uncut part of the cable and it 
can then be slipped off over the wire. 

After the armor has been cut away from the wire, a very 
rought jagged part of the armor is directly in contact with 
the wire. So that there will not be any destruction of the 
insulation on the wire at this point, the Code demands some 
protection be given. Between the wire and the end of the 
armor a fibre bushing must be placed. There are several 
types of connectors listed for securing cable to metal boxes. 
A straight Connector may be used for cable sizes 14-2, 14-3, 
12-2, 12-3 and 4-1. A 90 degree Connector is used where 
cable is brought down at an angle to the box in such a 
manner that it is impossible or impractical to use straight 
cable Connector. The 90 degree Connector will take cable 
sizes 14-2, 14-3, 12-2, and 10-2. The Duplex Connector is 
used where it is desired to bring two cables through same 
knockout of metal box. Connections to boxes supplied with 
clamps are simply made by removing the knockout and in- 
serting the end of the cable through the opening and into 
the clamps. The clamp is pressed down at an angle on the 
cable by tightening the screw. Almost any of the types of 




Page T\v k nty-foi j n 



ARMORED CABLE 




ARMORED CABLE 


FIBRE 
BUSHING STRAIGHT 


DUPLEX 


STAPLE 

t 


v- 


STRAP 


ARMORED CABLE 
CONNECTOR 

DRAWING No. 26 


CONNECTOR 



90° 
CONNECTOR 



outlet and switch boxes available can be used for armored 
eable. 

Armored eable must be supported at intervals not exceed- 
ing 4i/2 feet j and where run under building joist, as in 
basement installations, must be supported at each joist. 
A staple or clamp must be used to fasten cable within 12 
inches of every outlet switch or receptacle box except in 
eases where greater flexibility is desired such as con- 
nection to motors, in which ease not more than 30 inches 
shall be allowed between connection to box and first staple 
or strap. For securing cable to building surfaces, use either 
Cable Strap or Cable Staple. 

Where cables are run through joist or sills, holes bored 
in the wood should be at not less than 20 degrees angle as 
this will eliminate any drag on the cable. 

Exposed runs of cable shall closely follow the surface 
of the building finish or of running boards except lengths 
of not more than 24 inches at terminals where flexibility 
is necessary; in accessible attics and roof spaces for which 
the cable shall be installed as follows: 

Where run across the top of floor joists or within 7 feet of 
floor or floor joist across the face of rafters or studding. 
the cables shall be protected by substantial guard strips 
which are, at least, as high as the cable. If the attic is not 
accessible by permanent stairs or ladders, protection shall 
not be required within 6 feet of the nearest edge or scuttle 
hole or attic entrance. If carried along the side of rafters, 
studs or floor joists, neither guard strips nor running boards 
shall be required. 




DRAWING No. 27 



Wall Outlet for Old Construction 

To put switches in plastered walls. (Above right.) De- 
termine position of box and locate open space above and 
below lath. Place box open face towards wall directly over 
located lath, and trace outline of box. Cut center lath away 
and portion of top and bottom laths to accommodate box. 
Pull cable through opening and fasten to box. Place box 
in opening and fasten. For wallboard use support illus- 



trated in figure at left above. Attach to back of box by 
removing center knockout and inserting bolt and washer 
through inside of box. Attach clamp to bolt on the outside 
of box. Cut opening in wall exact size of box. Insert box 
and support. Tightening screw draws support firmly against 
wallboard from behind. 




iLma&omseeeim^adeoooaim 



' CEILINO 
LINE 




DRAWING No. 28 



Installing Ceiling Outlet 
in Old Construction 

For installing ceiling outlets on alteration or extension 
work first locate the position where fixture will be in- 
stalled and make a small hole about 1% inches in diameter 
in the ceiling. If this fixture is to be controlled by a wall 
switch, select a convenient location for it and make a hole 
in the wall just large enough to accommodate the switch 
box for this switch. Run the cable from the ceiling hole 
to that made in the wall. If the cable can be run parallel 
with the rafters simply fasten the cable to the nearest 
rafter and run it along to the wall partition where the 
switch will be located. Drop the cable down from a point 
above the proposed switch outlet and draw cable through 
the hole already made. 




DRAWING No. 29 



I \\C.K T WEN T V-FI VK 



Drawing No. 29, page 25, shows a surface type outlet made 
with armored cable, outlet box and box cover receptacle. Gal- 
vanized boxes are recommended for locations subject to 
dampness and vapors. To install this outlet first locate posi- 
tion for desired light and securely fasten the outlet box to 
the surface. Extend cable along surface leading to box and 
fasten to surface as described at left. Next strip ll/ 2 inches 
of insulation from the two cable wires and the two wires 
leading from the box cover receptacle. Then splice, solder 
and tape them together. The receptacle cover is then at- 
tached to the box, completing the installation. 




DRAWING No. 30 

COMPLETING CEILING AND 
SWITCH INSTALLATION 

On such installations shallow %-inch boxes are generally 
used in combination with a hanger and sliding fixture stud. 
Insert "old work" hanger and stud through ceiling open- 
ing, laying bar across the laths with stud in the center of 
opening. Pull cable through this opening and attach. With 
center knockout removed from box place box over stud and 
secure with locknut. Illustration shows ceiling cut away 
for box. Installation can also be made by simply laying- 
box against ceiling and tightening up on hanger locknut. 

To supply current to switch, run cable from the most con- 
venient "live" outlet to opening in wall and attach cable 
and that from the ceiling outlet to a switch box and place 
box in wall as described at left. 




DRAWING No. 31 

WALL OUTLET FOR 
NEW CONSTRUCTION 

The above illustrates two methods of installing switch 
boxes for use with wall switches, receptacles or wall 
brackets. If the switch is to be located between the two 
studs as shown in the larger illustration proceed as follows: 
Fasten securely two wood strips not less than %-inch thick 



to the studding, spaced to the dimensions of the switch 
length. If the installation is to be made in a deep partition, 
select the deep switch box. Shallow switch boxes should be 
used in shallow partitions. 

If the outlet is located next to studding, use switch boxes 
with bracket support. The bracket is fastened to the stud 
on one side and with the lath fitting into the slotted grooves 
on the opposite side of the box. The cable is attached to the 
box in the regular manner. 




DRAWING No. 31 A 



CEILING OUTLET FOR 
NEW CONSTRUCTION 

The boxes used for ceiling outlets must be at least \y 2 
inches deep. These boxes should be so installed so that 
the lower edge of the box will not protrude below the 
finished plaster line. Offset steel bar hangers secured to the 
underside of the studding are recommended. Illustrated is 
the typical illustration of ceiling outlet made with a com- 
bination box stud and bar hanger. By loosening the stud the 
box can be adjusted to the desired position. After removing 
the knockout from the box where the cable will enter, 
fasten bar to the underside of the studs and secure the cable 
to the box. The outlet is then complete and ready for hang- 
ing the fixture. 





CONNECTION 



DRAWING No. 32 

INSTALLING SWITCHES, 
RECEPTACLES, PLATES 

Wall switches and receptacles are of standard dimensions 
for installations in regular wall type boxes. After the wires 
are brought into the box, remove about % inch of the insula- 
tion from each wire and properly attach them to the con- 
tact screws on the switch or receptacle. Then j>ush the 
wires back into the box and attach the switch or receptacle 
to the box. It is fastened by placing it across the face of 
the box and inserting screws through the holes at each 
end into the threaded holes of the switch box. Switches 
are available in two types — push button and toggle — each 
with its own type of wall plate. 



Page Twenty-six 





DRAWING No. 32A 



DRAWING No. 33A 



INSTALLING WALL BRACKETS 

Sears Fixtures are furnished with all fittings necessary 
to install. Shown are fittings and installation made with 
a bathroom or kitchen bracket. All brackets are usually 
installed in this manner. Connect the wires leading from 
the bracket to those terminating in the switch box, and 
push stripped ends of wires to be joined into connector. 
Then push and turn connector until tight. No solder or 
tape needed. Secure the strap to the box and fasten the 
nipple to the strap through the center hole. Then place 
the bracket over the box so that the nipple will extend 
through the hole in the bracket. Place the knurled cap over 
end of nipple and tighten. 



HANGING KITCHEN CEILING 
FIXTURES 

Furnished with this type fixture is one strap, one %-inch 
locknut, two machine screws and two solderless connectors. 
Install as follows: Place the hole in the center of the strap 
over the fixture stud in the box and fasten it there with 
the locknut. Then bring the fixture holder up to the ceiling 
and connect the wires from the box and fixture with the 
connectors. Place the holder next to the ceiling so that the 
small holes in the holder are directly over the threaded 
holes in the strap. Using the machine screws secure the 
holder tightly against the ceiling and then attach the glass 
shade to the holder. 




DRAWING No. 33 



HANGING CEILING FIXTURES 

With the parts provided with your Sears LIGHTMASTER 
Fixture, proceed with installations as follows: Loosen the 
canopy from the fixture stem and attach to the end of the 
stem a fixture hickey. Next attach the hickey to the fix- 
ture stud. With solderless connectors, join the two wires 
that lead from the fixture to those in the outlet box. Make 
sure that exposed parts of wires are completely inside 
the connectors. Push the canopy so that it fits close to the 
ceiling and tighten nut on the side of the canopy against 
the center stem. Or if the canopy on your fixture is held 
with a locknut at the bottom of the canopy simply tighten 
up on this locknut. 



NON-METALLIC SHEATHED CABLE 



DRAWING No. 34, PAGE 28 



Non-metallic sheathed cable (often referred to as "Ro~ 
mex") may be used indoors the same as armored cable but 
should not be installed in masonry or plaster. A low cost 
wiring product, it is designed for use in residences, and 
small buildings. It consists of copper wires, with rubber 
insulation covered with a heavy cotton braid jacket impreg- 
nated with moisture and flame retarding compounds. 
Sheathed cable is particularly suitable for barns and out- 
buildings where moisture and acid vapors are prevalent. 
Easy to install, it can be attached to the surface, pulled 
through partitions or floor joists and can be used for 
power or lighting circuits. 



Figure 1 illustrates method of removing outer sheathing 
from wires. Inside the sheathing is a heavy ripcord which 
when gripped and pulled splits the outer insulation, which 
then can be easily removed. 

Figure 2 is the type of strap used to fasten cable to the 
surface. 

Figure 3* is the usual type of connectors used to fasten 
cable to switch and outlet boxes. Simply insert end of cable 
into connector and tighten clamp screws. The locknut on the 
connector secures the connector to the box from the inside. 
The various types of installations shown here are used for 
both armored cable and non-metallic sheathed cable. 

Page Twenty-seven 




ILLUSTRATION No. 34 



INSTALLATION OF SHEATHED CABLE 



Non-metallic sheathed cable consists of two or more rubber 
covered conductors bound closely together by an outer braid 
of cloth saturated with a compound to give it slow burning 
qualities. It is frequently used in dairy barns, chicken 
houses and similar locations where a metallic cable would 
be affected by fumes and has found increasing use for 
ordinary house wiring. 

Where cable enters an outlet box, outer protective cover- 
ing is to be removed and Romex Connector securely fast- 
ened to the outside covering of cable (see Drawing below). 
The connector is then run through hole of outlet box, and 
lockout brought up tightly so that any possible vibration 
will not loosen same. In the wiring of a new home, straps 
must be used regardless of whether cable will be hidden or 
left exposed outside of joist or sills. All splices and con- 
nections shall be made within the enclosing wall of an outlet, 
switch or receptacle box. 

If the cable is run at angles with joists in unfinished 
basements, assemblies not smaller than No. 6 or 3 No. S 
conductors may be secured directly to the lower edges of the 
joists. Smaller assemblies shall either be run through bored 
holes in the joists or on running boards. Where run parallel 
to joists, cable of any size shall be secured to the sides or 
face of the joists. 

In exposed work, except under certain provisions which 
will be given below, the cable shall be installed as follows: 
The cable shall closely follow the surface of the building 
finish or of the running boards. It shall be protected from 
mechanical injury where necessary by conduit, pipe, guard 
strips or other means. If passing through a floor, the cable 
shall be enclosed in rigid conduit or pipe extending at 
least 6 inches above the floor. Cable in accessible attics or 
roof spaces shall be installed as follows: If run across 
the top of floor joists^ or within 7 feet of floor or floor 
joists, across the face of rafters or studding the cable shall 
be protected by substantial guard strips, at least, as high 
as the cable. If the attic is not accessible by permanent 
stairs or ladders, protection will only be required within 6 
feet of the nearest edge of scuttle hole or attic entrance. 

If carried along the sides of rafters, studs or floor joists, 
neither guard strips nor running boards shall be required. 

Bends in cable shall be so made, and other handlings shall 
be such that the protective covering of the cable will not 
be injured. 

Page Twenty-eight 



The cable shall be secured in place at intervals not ex- 
ceeding 4I/2 feet and within 12 inches from every outlet box 
or fitting except that in concealed work in finished build- 
ings where such support is impracticable the cable may be 
fished from outlet to outlet. 



DRAWING BELOW SHOWS 

INSTALLATION OF NON-METALLIC 

SHEATHED CABLE WITH SWITCH 

AND OUTLET BOX 




ILLUSTRATION No. 35 



KNOB AND TUBE WIRING 




® GLAZED 
SPLIT KNOBS 
® NON-METALLIC 
LOOM 
©TWO WIRE 
CLEATS 
©ONE-PIECE 
ROSETTE 
©DROP CORD 
CLEAT 

(g) RECEPTACLE 

(6) TUBES 

®DROP CORD 
ROSETTE 

H\ CLEAT 
W RECEPTACLE 

(g) RECEPTACU 



Illustrated are the loom and porcelain 
accessories commonly used in "knob and 
tube" wiring. Rubber covered wire is used 
with knobs or cleats to hold the wire to 
the surface and must beat least 2 >/ 2 inches 
apart when run over an exposed surface. 
If the wires are concealed, they must be 
not less than 5 inches apart and 1 inch 
from surface. When these dimensions 
cannot be followed each wire must be 
covered with loom. 

Cleats and knobs supporting the wire 
must not be spaced further than 4 V 2 feet 
apart, and the wires between such sup- 
ports must not sag but should be pulled 
taut. 

This type of wiring is not approved in all 
localities. Consult your local authority 
before making installation. 









OPEN TERMINAL 








X^CLEAT 


_xlLsl^ 


_/ RECEPTACLE 
IIP? 


dK^T*^ 


'PJ7|^J^ ? I 




PI 






J| 


-*_____! 












M 


^Cpfr', 











WIRE 




>-TUBE 


KNOB 

^-LOOM 


OUTLET 
1 BOX 








W 1 >^. 1t>>J ^Miu^ , 










pG] 




.BAR 
HAts 


GER 










^^*xL^ 






N 




DRAWING No. 36 



P A G E T WE K T V- X I N E 



KNOB AND TUBE WIRING 



Knob and tube wiring is probably the oldest form of elec- 
trical wiring still being used in many locations today where 
local codes permit. Its chief advantage is low material cost 
because it requires only the use of rubber covered wire in 
combination with porcelain fittings and holders. The use 
of rubber covered wire and porcelain fittings in knob and 
tube wiring is subject to definite rulings by the National 
Board of Fire Underwriters. In the usual type of installa- 
tion, rubber covered wire is used — other special heat resist- 
ant wires are specified where the constant temperatures 
exceed 120 degrees Fahrenheit. 

Conductors should be supported at intervals not exceed- 
ing 4>y 2 inches by knobs and tubes and separated at least 
3 inches apart and maintained at least 1 inch from the 
surface. Where space is limited and this 3-inch separation 
cannot be maintained each conductor must be encased for its 
entire length within the wall surface in a non-metallic 
sheath known as "loom." Where practicable, conductors 
shall be run singly on separate timbers or studding. Wires 
passing through cross timbers in plastered partitions shall 
be protected by an additional tube extending at least 3 
inches above the timber. 



Conductors in unfinished attics or roof spaces shall 
comply with the following: Conductors in unfinished attics 
and roof spaces shall be run through or on the sides of 
joists, studs and rafters except in attics and roof spaces 
having head room at all points of less than 3 feet in build- 
ings completed before the wiring is installed. If conductors 
in accessible unfinished attics or roof spaces reached by 
stairway or permanent ladder are run through bored holes 
in floor joists, or through bored holes in studs or rafters 
within 7 feet of the floor or floor joists, such conductors 
shall be protected by substantia] running boards extending 
at least 1 inch on each side of the conductors and securely 
fastened in place. If carried along the sides of rafters, studs 
or floor joists, neither running boards nor guard strips will 
be required. 

Where wires run through joist and sills, the wires must 
be run through porcelain tubes as shown on Drawing No. 42. 
These tubes shall be placed through a beam or joist at an 
angle of not less than 20 degrees to the perpendicular. 
Split porcelain knobs or cleats must be used to securely 
fasten the wires before the connection to the porcelain 
fitting or receptacle or where a splice is made. 



Illustration "L" shows an ordinary knob and tube installa- 
tion on page 29. Note the wires are drawn taut and the dis- 
tance between wires is uniform and not less than 2 l / 2 inches. 
Holes have been made through the joists at a downward 
angle with tubes inserted so that the large end is at the high- 
er level, preventing the tube from slipping out of the hole. 
Such tubes must always be used when running wires through 
joists or studding and can be had in various lengths to 
accommodate the thickness of the obstruction. 

Illustration "M" shows surface installation and outlet 
made with cleats and open terminal receptacle. The wire is 
run through the grooves in the cleats spaced 2l/2 inches apart 
and drawn taut between cleats. When you have selected the 
location for the receptacle, place it between the wires and 
mark location on each wire, of the contact screws of the re- 
ceptacle. Then strip a small part of the insulation from each 
wire, where marked and slip this under the receptacle con- 
tact screw. Complete installation by securing receptacle to 
surface. 



Illustration "N" shows ceiling outlet installation using 
knobs and tubes. A %-inch hole for each tube is drilled 
through the joist for the porcelain tubes through which the 
wires are run to the box. Note the use of loom where the 
wires are brought closer to each other and to the surface 
before entering the box. Use the same type of ceiling box as 
shown under the heading of Armored Cable Wiring, In- 
structions for installing are also given. 

Illustration "P" shows wall outlet installation in new con- 
struction using Rubber Covered wire, loom and porcelain 
fittings. The wires have been run along the studding and 
fastened with knobs up to the point where the box is located. 
The branch wires leading to the box have been spliced, 
soldered, taped, and fastened with a knob to the studding. 
As each wire leading from the splice to the box is closer to 
the surface or to the other wires than permissible, they have 
been covered with loom from the point where the splice is 
made, on up into the box. 



OUTLET, SWITCH AND JUNCTION BOXES 

AND FITTINGS 



An outlet box is an enclosure in either round, square or 
octagon shape furnished with a number of knockouts so 
that cable or conduit may be connected with it. It serves 
as a protector against mechanical injury to the wires en- 
closed within its walls. Outlet boxes are used for the pur- 
pose of making splices or connections, and when covered 
with a blank plate are known as junction boxes. They are 
used to form the enclosure for protecting connections to 
fixture leads and are sometimes used in surface wiring for 
mounting switches and convenience receptacles. 

Switch or receptacle boxes, as their name implies are 
used to mount switches or receptacles either in the wall or 
on the surface and are protection for the wires connected 

Page Thirty 



or spliced within their walls. Outlet and switches and re- 
ceptacle boxes are made of steel, porcelain and bakelitc. 
The use of porcelain and bakelite boxes is restricted, and 
before considering their use, check with your Power Com- 
pany or Inspection Agency for their recommendations. 

Steel boxes are furnished in either black enamel or gal- 
vanized finish. The galvanized finish is usually preferred as 
it permits better grounding of the box. 

Steel switch or receptacle boxes are furnished in several 
sizes and types (see Drawings on opposite page), however, 
the most common are the 2 1 / 4~inch deep sectional switch or 
receptacle boxes. Sectional boxes are so named because their 
sides are removable permitting two or more box frames to 



8 








o 

D El 





I W J 








c 




Page Thirty-one 



be joined or ganged to make a larger box for mounting 
two or more switches or receptacles or both in one unit to 
be covered by one plate. 

Boxes and fittings are installed at all outlet and switch 
points (see Drawing No. 13, page 14). Round outlet boxes 
should not be used where conduits or connectors requiring 
the use of locknuts or bushings are to be connected to the side 
of the box. Boxes used to enclose receptacles or switches 
shall be of such design that they w T ill be completely en- 
closed on back and sides and that substantial support for 
them will be provided. Outlet boxes for concealed work 
shall have an internal depth of at least iy 2 inches except 
where the installation of such a box will result in injury 
to the building structure or is impracticable. Then a box 
not less than l/ 2 inch internal depth may be installed. (If 
in doubt, inquire at your local inspection office.) In com- 
pleted installations, each outlet box shall be provided with 
a cover unless a fixture canopy is used. 

Non-metallic covers and plates shall be used with non- 
metallic outlet boxes except that a metal cover or plate 
may be used if covered on the exposed side with non- 
metallic material. Screws shall not be used for fastening 
such covers or plates to non-metallic boxes unless located 
in such positions that they cannot come in contact with live 
parts or live conductors in the box or unless the exposed 
screw heads are covered with non-metallic material. Boxes, 
fittings and cabinets shall be securely fastened in place. 
Boxes and fittings, not over 100 cubic inches in size which 
are attached to firmly secured exposed raceway by threading 
or other connections designed for the purpose are consid- 
ered as so fastened. 

In concealed work, outlet boxes and fittings, unless se- 
curely held in place by concrete, masonry or other building 
material in which they are embedded shall be secured to 
a stud, joist or similar fixed structural unit or to a metal 
or wooden support which is secured to such a structural 



unit. Wooden supports shall not be less than 7 / s inch in 
thickness. Lack of wood, metal or composition shall not 
be considered a structural unit. In exposed work and in con- 
cealed work in existing buildings where conductors or cables 
are pulled and outlet boxes cannot be secured as provided 
in the above paragraph, without disturbing the building 
finish the boxes may be mounted directly upon the plaster 
surface if securely fastened in place. 

Outlet boxes used where gas outlets arc present shall 
be so fastened to the gas pipes as to be mechanically se- 
cure. In walls and ceilings constructed of wood or other 
combustible material, outlet boxes, fittings and cabinets 
shall be flush with the finished surface or project there- 
from. 

Where raceway or cable is used with metal outlet boxes, 
fittings or cabinets, the raceway or cable shall be secured 
to outlet boxes, fittings and cabinets and the conductors 
entering the box, fitting or cabinet shall be protected from 
abrasion and the openings through which the conductors 
enter shall be adequately closed. 

Non-metallic outlet boxes may be used only with open 
work, concealed knob and tube work, non-metallic sheathed 
cable and with non-metallic waterproof wiring. In open 
wiring and knob and tube work, the individual conductors 
shall enter the non-metallic box through individual holes. 
Where flexible tubing is used to encase the conductor be- 
tween the last support and the box, this may be run into 
the box or terminated at the wall of the box. Where non- 
metallic sheathed cable is used with non-metallic outlet 
boxes, the cable assembly shall enter the box through a 
knockout opening. Clamping of individual conductors or of 
cables to boxes is not required if supported within 6 inches 
of the box. In moist places, boxes, fittings and cabinets 
shall be so placed or equipped as to prevent moisture from 
entering and accumulating within the box, fitting or cabinet. 
Boxes, fittings and cabinets installed outdoors shall be 
weatherproof. 



GANGING OF SWITCH BOXES 




FIRST STEP 
REMOVE END WALLS 



SECOND STEP 
FIT BOXES TOGETHER 

DRAWINGS No. 38-39-40 



THIRD STEP 

DRAW UP SCREWS 

12 GANG BOX) 



When more than one outlet is operated from a given point, 
as for instance two or more switches at one location, to op- 
erate lights in different rooms, it is desirable to group such 
switches, receptacles, etc. under one switch plate. This is 
called ganging. 



Switch boxes are constructed so that any number of 
them can be ganged together. The two sides of each box 
are removable and can be fastened to each other by remov- 
ing one side of each box, placing them together and tight- 
ening into place. Switch and outlet boxes arc made in black 
enamel and galvanized finish. 



Page Thirty^-two 



CHAPTER flVE 

TYPES OF SERVICE ENTRANCE 



Service entrance installations may be made with service 
entrance cable, electrical rigid conduit with rubber covered 
wire- — and thin wall conduit with rubber covered wire. The 
materials you use depends entirely upon your state or local 
code requirements. Drawing No. 4S, page 34 illustrates an 
entrance service installation made with service entrance cable 
and fittings. The use of these materials for this purpose has 
increased tremendously during the past 2 years ; its prin- 
cipal advantages are low material and installation costs, 
and should be installed as follows: An entrance head should 
be mounted not less than 15 feet from the ground and a 
three wire No. 6 armored service entrance cable type SE- 
ABN be run from entrance head to meter socket ring 




® 



m 



DRAWING No. 41 

mounted approximately 5 feet from ground. Figure No. 13, 
page 84 illustrates an enlarged section of service entrance 
cable showing its construction. This is a three wire cable, 
and you will note only two of the wires are insulated. The 
third wire consists of various small stranded wires that are 
wrapped around the two insulated wires. When it is neces- 
sary to attach this bare third wire to a switch or meter, the 
separate stranded wires are simply gathered together and 
twisted to form apparently one wire. 

Note that we have used a cable consisting of" 3 No. (> 
wires on this installation. Your Power Company will prob- 



ably also suggest the use of this size cable for a 60 ampere 
service. Service entrance cable can be supplied in either 
two or three wires, in various combinations of wire sizes. 
What you use depends upon the recommendations of your 
Power Company or local inspectors office. At the service 
head, the cable is stripped of its outer cover and fastened 
to this fitting with each of the three wires extending through 
the holes in the service head. In cutting the cable, allow- 
ance should be made to have these wires extend from the 
holes in the service head at least 24 inches. 
To hold service entrance cable in meter ring, it will be 
necessary to use two watertight connectors — one where 
cable enters ring, and one at bottom of ring where cable 




DRAWING No. 42 

leaves meter ring. Service cable straps should be used 
to hold cable to building and spaced approximately 
every four feet. The cable is brought from bottom of 
meter ring through wall and into main service switch which 
should be located within one foot of where cable passes 
through inside of building. The cable is secured to main 
switch box through the use of one non-watertight service 
cable connector (See Drawing No. 43, page 34). 

This switch is of 60 ampere capacity and is the same 
type that is often used on services of this size in combi- 
nation with entrance cable. State, local and power com- 

Page Thirty-three 




Pace Thirty- foui 



BL. W. BL. W. BL. W. BL, W. W. BL. 



TO POWER 

COMPANY 

LINES 




Page Thirty- five 



panics specifications cover the size and type of equipment 
you should use. Consult them before ordering a service 
switch. All Sears entrance switches are supplied with wiring 
diagrams. In selecting a type of service entrance s witch , you 
ha\e a choice between a fused switch and a new automatic 
protective switch known as a "No-Fuze" load center switch. 
The "No-Fuze" load center switch eliminates all fuses and 
protects the circuit by its automatic mechanism which is 
fool proof and tamper proof. See drawing No. 42 A, page 33. 

The function of this "No-Fuze" load center switch is: 
In the case of an overload or short in any circuit of your 
wiring, an automatic device trips out the switch, automati- 
cally relieving the pressure caused by the short or overload 
on said circuit. "No-Fuze" load center switch panels are 
provided in two types: A flush unit which permits the in- 
stallation of your panel flush with the wall surface on your 
first or second floor, thereby in many cases reducing cost of 
wiring — or surface type for mounting in basement or out- 
buildings. 

Connections of cable to main service switch used in illus- 
tration No. 4»3, page 34 are: Black wire of service entrance 
cable connected to left hand lug of 60 ampere main. Red 
wire is connected to right hand terminal of 60 ampere main. 
The concentric bare wire is twisted together and connected 
to nickel plated neutral bar located in top of switch box. A 
bare copper wire either No. 6 or No. 4 gauge is connected 
to neutral bar and run to either water or artificial ground 
(See Chapter No. 6 on Grounding). Your range connections 
will be: Black wire of range cable connected to left hand 
terminal of 45 ampere range circuit. Red wire is connected 
to right hand terminal of range circuit. White wire of 
range cable is connected to third lug of top neutral bar. 
It will be noted that there is a direct connection between 
top neutral bar and bottom neutral bar. All connections of 
16 and 20 ampere branch circuits must be made as shown 
in drawing. With black wires connected to the fused ter- 
minals and white wires connected to the neutral unfused 
terminals. Drawing No. 43 shows that between each pair 
of branch fuses there is an additional lug which is un- 
fused. This switch was purposely designed so that an 
unfused 220 volt line could be run as a sub-feed to another 
switch located in some other position such as a safety switch 
for protection of pump motor or operation of electric water 
heater. Under no circumstances are any of your branch 
circuit lines to be connected to these unfused lugs. 



CONDUIT SERVICE ENTRANCE 



Figure No. 44, page 35 illustrates an entrance service in- 
stallation made with galvanized rigid conduit and rubber 
covered house wire. Galvanized conduit is usually installed 
on outside of building although in some localities black 
enameled conduit may be used. The entrance cap is fastened 
to the conduit and fastened to the meter rings at bottom of 
meter ring; another piece of conduit is installed which runs 
down to a point where the service is to enter building. At 
this end, an entrance ell is placed on conduit. This ell has 
two threaded holes corresponding to the conduit size with 
which it is used. Into the threaded hole running at right 
angle to conduit from the meter ring, another piece of con- 
duit is placed which runs through a hole in the foundation 
and into the entrance switch in basement. 

With the cover on the entrance cap removed, three rubber 
covered wires are pushed up the conduit from the meter ring 

P AG E Till RT Y -SIX 



into and out of the service head allowing each wire to 
extend beyond service head about 24 inches. Each wire is 
run through one of the holes in the cover and the cover 
replaced. The wire connections are then made in the meter 
ring and continued down through to Entrance Ell. To 
facilitate the running of these wires at right angle, the cover 
on Ell is removed and the wires pulled all the way through 
and then fed through conduit leading to switch. 



30 AMPERE SERVICE 



From a service head a 3 wire No. 8 service cable (3 No. 8 
wires in conduit), is run through meter socket and outside 
wall of building and into an entrance service switch. It 
will be noted, see drawing No. 45. page 37, that there are 
three connections already made in this switch, therefore, it 
will be necessary to make only the following connections: 
Black wire from meter to left brass terminal at bottom of 
top section of switch. Red wire from meter to right brass 
terminal at bottom of top section of switch and bare (white 
in conduit wiring) wire from meter is connected to left 
nickel terminal at top of switch. A ground wire is attached 
to the right terminal at top of switch block. 

The branch circuits arc connected as follows: Black wires 
to the 4 brass terminals located one in each corner of the 
lower double block. White wires to nickel plated terminals 
at the bottom of branch circuit block. For 2 wire service, 
single pole solid neutral combination service entrance switch 
shall be used and connections shall be same as for the 3 
wire except that there is no red wire nor is there any place 
in switch where it could be connected. Consult with your 
power company or inspection office representative as to the 
proper type service switch to be used in your locality. 



OUTDOOR POLE MOUNTED SERVICE 



As shown in Drawing No. 46, page 38. when an outdoor 
service switch is required or desired, it will be necessary 
to use a special switch known as "weatherproof" type. 
You will note in drawing that power company lines termi- 
nate just below cross arm on pole and are there connected 
to leads of a three wire service cable (or 3 leads from a 
conduit run). 

End of cable (or conduit) is protected by a weatherproof 
service head, which, in the case of service cable, is securely 
mounted on pole, and serves also as a support for the top 
of the cable. Whether conduit or service cable is used, 
service head should be mounted 15 feet above ground, and in 
no case, can it be lower than 10 feet from ground. Regard- 
less of whether conduit or cable be used, supporting straps 
must be placed every 4 feet of run from head to meter 
socket. A short metal nipple may be used between meter 
socket and service switch. 

A grounding agent in the form of armored bare wire, 
wire protected by conduit or other approved means con- 
nected to an 8 ft. driven ground rod should be used. 

A duplicate of your entrance service run shall be returned 
up pole and lines then run to house. Where service enters 
house, another disconnecting switch shall not be necessary 
if there are not more than six circuits in house, and if 
branch circuit panel is located immediately adjacent to 
where service conductors enter building; however, it will 
be necessary to install a second grounding device. 




DRAWING No. 45 



bonding — *- ftn r~i riff 

BUSHING \ *M , ^' b ^-V 

f^r f 




P A U E T 1 1 1 IIT V - S E V E N 







DRAWING No. 46 



mmwmmmm7MW/, 



Page Thirty-eight 



UNDERGROUND SERVICES 

Underground sub-services from one building to another must 
have conductors protected by one of the following coverings: 

LEAD CABLE IN CONDUIT— See Drawings Below 

Consisting of two or more rubber covered conductors en- 
cased in a lead sheath and pulled through a metal conduit. 
This is the most common type of underground wiring. The 
initial cost of conduit and lead underground wiring is higher 
than either parkway or armored lead cables, but in the long 




DRAWING No. 47 

run is more practical. In the event of replacement of con- 
ductors, it is onl} T necessary to attach the new conductors to 
the old, and as the old cable is withdrawn from the conduit, 
the new cable is pulled through. 

Where cables of an underground service enters a building, 
they shall have mechanical protection in the form of rigid 
or flexible conduit, thin wall conduit, the metal tape of a 
service cable approved for underground installation or other 
approved protection. 

Where an underground service raceway enters a building. 
the end within the building must be sealed with a suitable 
compound so as to prevent the entrance of moisture or gases. 
There shall be no splices within a conduit, and where con- 
ductors larger than Xo. 6 are used, they shall be stranded. 

ARMORED LEAD CABLE 

Armored lead cable (type ACL) may be used under ground 
as a sub service feeder and consists of two or more rubber 
covered conductors encased in a lead sheath and the whole 
covered with a spirally wound flexible armor. 

PARKWAY CABLE 

Parkway Cable is furnished in two types, the metallic or the 
non-metallic, and may be buried directly in the earth without 
further covering or protection except that in the case of 



non-metallic cable where it enters a building, it must have 
mechanical protection in the form of conduit, flexible armor 
or other approved means of protection against mechanical 
injury. Both types are approved by the Code, however, 
before using either, inquire from your Local Power Com- 
pany or inspection office as to which type is preferred in 
your locality. 

When an underground service connects to Power Com- 
pany lines on a pole, conduit or cable (properly protected 
against mechanical injury by conduit or other approved 
means) shall be run up jiole to a minimum height of 8" 



DRAWING No. 48 




above ground. However, it is preferable to end run closer to 
Power Company cross arm or bracket so as to make a 
neater completed job. See your Power Company representa- 
tive for his recommendations. Underground sub-service, if 
not continuous metallic shall be grounded at branch panel 
in out building. 

For outdoor overhead wiring, a weatherproof wire type WP 
shall be used. (See Drawing No. 49, page 4-0 for outdoor 
work.) 

OVER-HEAD WIRING 

SEE DRAWING No. 50— Page 41 

For pole line construction, the most economical method of 
placing insulators is: Place 1 Porcelain Insulator equipped 
with a 2 l/o inch screw on top of pole and one or more In- 
sulators on opposite sides of pole, each insulator being at 
least 18 inches apart center to center of wire groove. The 
Oak Bracket used with porcelain Insulator is probably one 
of our oldest methods of carrying wires and is still accepted 
and approved by the Code. There are better means of sup- 
porting wires such as the above mentioned method or by 
the use of channel bracket on which two or three insulators 
may be screwed. This bracket is approved in most areas for 
short, overhead runnings or for supporting wires on the 
sides of buildings. 

Page Thirty -nine 




DRAWING No. 49 



Pack Forty 






POST INSULATOR 
EQUIPPED WITH 
SCREW 




INSULATOR 
FOR OAK 
BRACKET 




OAK 
BRACKET 



DRAWING No. 50 



An overhead sub-service between two buildings on the 
same property should be installed in the following manner: 
Either conduit or service entrance cable may be used for 
vertical runs on the outside of house and outbuilding. Runs 
start from your main service panel, preferably from the 
unfused tap of panel,, and are carried up outside wall of 
building to a service entrance head. A loop is made from 
head to a 2 or 3 wire insulator bracket located not less 
than 15 ft. from the ground. Wires are then carried over- 
head to similar equipment located on outbuilding (Sec 
Drawing No. 4s9, page 10). Sub-service is then run to 
a branch service switch in outbuilding and distributed 
from there to outlets in building. It will be necessary to 
ground bushing holding conduit or service cable in branch 
service panel as well as the panel itself. This is required 
because there is not a continuous metallic ground from main 
service panel to branch service panel. When service is de- 
sired in other buildings, this process must be repeated with 
a protective device located in each building and grounded 
at each building. 



3-WAY CIRCUITS BETWEEN 
BUILDINGS 

\\ hen a 8 way circuit for controlling a yard light from 
two buildings is desired, it will be necessary to follow this 
rule: A conduit or service entrance cable is run from 3 way 
switch in both buildings vertically on outside surface of 



buildings terminating in a service entrance head. A loop 
made from a 3 wire bracket (See Drawing No. 51, page 42) 
on which are mounted the following: One 3 wire bracket. 
one screw type Insulator and one Outdoor Heavy Duty 
Light Bracket. 

The wiring shall be: — Two wires from branch circuit 
panel in house are run to 3 way switch in bouse; black 
wire connects to bronze terminal of 3 wav switch; white 
wire to white wire from conduit (bare wire of service 
cable) ; black and white wires in conduit or service cable 
connect to brass terminals of 3 way switch. Wires arc then 
run outside and overhead to pole in yard (outside wires 
must be weatherproof). Black wire from hoirje 3 way 
switch is to be connected to top wire on bracket, we will 
call this wire No. 1 ; red wire is connected to second wire 
No, 2; white wire is connected to lowest wire No. 3, Wires 
No. 1 and No. 2 continue unbroken from house to barn; 
No. 3 from house is fastened to screw type Insulator and 
looped down to weather proof outdoor light bracket, there 
connected to the white wire of light bracket. Wire No. 3 
from barn is fastened to lowest insulator of bracket mounted 
on pole, looped down to outdoor light bracket and connected 
to black wire of light bracket. It will be necessary to remove 
coating at both ends of white wire of 3 wire line in barn 
after run is made and you are sure of the identity of tile 
wires. If service cable is used at barn end of 3 way circuit, 
it will be necessary to use a cable consisting of 3 insulated 
wires; the regular service cable of 2 insulated and 1 bare 
should not be used. 



Page Fokty-oxis 







DRAWING No. 51 



Page Forty-two 



CHAPTER SIX 

SPLICING AND GROUNDING 



Every splice or connection of wires except where fixtures 
are connected to leads from outlet boxes must be soldered 
and covered with both rubber and friction tapes. The use 
of both tapes is necessary for in stripping wires to make 
connections you have removed both rubber and cloth cover- 
ing from the wire's. This covering must be replaced, there- 
fore j after splice is made and soldered, a piece of rubber 
tape is wrapped around splice and as each wrap is made tape 
is pulled very tightly around wire. At end of splice, end 
of tape is merely pushed down on insulation of wire where 
it will hold itself because of the elastic qualities. The 
rubber tape is then covered by friction tape which acts as 
a seal preventing air as far as possible — causing a disinte- 
gration of the rubber. 

Where drop cords are connected in outlet boxes and in 
sockets protection must be used to prevent stress or pull 
on the splice. One method of accomplishing this purpose 
is: the Underwriters' "Knot" as shown in illustration No. 53, 
page 44. 

SPLICING CABLE 




DRAWING No. 52 

Joints or splices made with cable must be in a steel box as 
shown. Remove required number of knockouts from box and 
fasten to surface. Measure cable to point where it will 
terminate in box allowing at least 8 inches extra for splicing. 
Strip armor from this portion of cable and insert fibre 
bushing and connector over end of armor. Fasten cable 
to surface with cable staples, not less than 41/q feet apart, 
pulling the cable taut as each fastening is made. Place 
connector into box and fasten. Strip about ll/o inches of 
insulation from each of the 4 wires and splice as shown. 
Apply soldering paste to each s}:>lice and heat splice 
enough to melt solder as applied. Wrap splice with rubber 
and then with friction tape. 



"^"^ 



LINE SPLICE 




FIRST STAGE 



GROUNDING 

Means of Grounding: You must use a ground on every 
electrical system so as to give adequate protection to your 
wiring system — a protection against defects or deterioration 
in the transformer causing a voltage surge on your lines— 
or lightening striking the exterior lines, which, if there was 
not an effective ground on your house wiring system, might 
cause considerable damage to your wiring and electrical 
devices. The Underwriters' have therefore laid down strict 
rules covering the construction of grounds and grounding 
devices for protection of your circuits. This, of course, 
is to your advantage. 

The path to ground from circuits, equipment or conductor 
enclosures shall be permanent and continuous and shall be 
of a size great enough to safely conduct any current that 
it might be called upon to carry, and the wire used for 
grounding conductor shall be of the same size or larger 
than the wire used for service entrance. It shall be securely 
connected to clamps or other grounding devices, and ground- 
ing device located, in the ease of an artificial ground, below 
the line of permanent moisture. This will be covered at 
greater extent in following paragraphs. For overhead serv- 
ices, the following shall be bonded together by means of 
bonding jumpers, clamps, or other devices (not locknuts 
and bushings) aprjroved for the purpose: 

a. The service raceways or service cable armor or sheath. 

b. All service equipment enclosures containing service 
entrance conductors. 

c. Any conduit, pipe, or armor which forms part of the 
grounding conductor to the service raceway. 

If there are cabinets, meter fittings, boxes or gutters 
interposed in the service raceway or armor, or in the 
grounding conductor of the service raceway or armor, the 

electrical continuity of the system shall he assured by one 
of the following methods: 

a. Threaded fittings with joints made up tight, where 
rigid conduit is involved. 

b. Threadless fittings, made up tight, for electrical 
metallic tubing. 

e. Bonding jumpers meeting the other requirements of 
this article. 

d. Other devices (not locknuts and bushings) approver 1 
for the purpose. 



smsmmm 



TAP SPLICE 



mimmrfmumiwL.uuiL-*- 977^^777^-^11/ sBmBBBBBaMBM 

LINE SPLICE FINISHED SPLICE 

DRAWING No. 52A 




Page Forty-thhee 






A \^^nttr5jaborafon>ir^ 

^ TESTED AND INSPECTED *" 


R.C.WIRE 1 

^" 25 FT. """^ 





M^ttDnttts* laboratories Tf n 

» W INSPECTED "ftC. 



ARMORED C A6l r 
US 



^/^ INSPECTED ^V'v 
/{ ^ENCLOSED SWITCH V 



ISSUE 



^ INSPECTED flf - 

SERVICE EQUIPMENT 

FORM 

ISSUE 



z 

OS 

o 


Underwriters' Laboratories, Inc. 
INSPECTED WIRED 
ELECTRIC FIXTURE 




MANUFACTURERS NAME 






^•wfflSSKS^^ 


It 




NON-METALLIC 

SHEATHEDCABLE 

^-^"200 Ft. ^-^ 






NO. 





Pace Forty-four 



DRAWING No. 53 



FOR UNDERGROUND CARLE: 

Service conduit or metal pipe from underground supply is 
considered to be grounded if it contains metal sheathed cable 
bonded to a continuous underground metal sheathed cable 
system. The sheath or armor of service cable from under- 
ground supply is considered to be grounded if it is me- 
tallically connected to a continuous underground metal 
sheathed cable system. 

GROUNDING ELECTRODES: 

Water Pipe; A continuous metallic underground water 
piping system shall always be used as the path of the 
current to the ground where such piping system is available. 

ARTIFICIAL GROUNDS: 

Where such a water piping system is not available the 
grounding connection shall be made in a manner to secure 
the most effective ground. Any one or combination of the 
following may be used: 

a. The metal frame of the building, if effectively 
grounded. 

b. A continuous metallic underground gas piping system, 
e. A local metallic underground piping system, metal 

well casing, and the like, 
d. An artificial ground whose electrode consists of a 
driven pipe, driven rod, buried plate, or other device 
approved for the purpose. 

GAS PIPING 
FOR FIXTURE GROUNDING 

Gas piping may serve as the path to the ground for fixtures 
located at a considerable distance from water piping. Where 
gas piping is so utilized, it shall be bonded from the house 
side of the gas meter to the water piping system. If no 



water piping is available, a bonding jumper shall be used 
around the gas meter. Gas piping need not be insulated from 
otherwise well grounded fixtures. 

COMMON ELECTRODE: 

If buried plates or driven rods or pipes are used, the ground- 
ing conductor for conduit, cable armor, and other metallic 
race-way or wire enclosure, or for equipment shall have its 
own grounding device, separate from the grounding device of 
the wiring system or the secondary distribution system 
supplying it, unless such distribution system has, at least, 
one additional ground at the transformer or elsewhere. 

SIZE AND LOCATION 

Where artificial grounds are used the rods, pipes or plates 
shall, as far as practicable, be embedded below permanent 
moisture level. Each buried plate electrode shall present 
not less than two square feet of surface to exterior soil. 
Electrodes of plate-copper shall be at least 0.06 inch in 
thickness. Electrodes of iron or steel pipe shall be galvan- 
ized and not less than %." internal diameter. Electrodes of 
rods of steel or iron shall be at least %" minimum cross 
sectional dimension. 

Approved rods of non-ferrous materials such as copper 
or their approved equivalent used for electrodes shall be 
not less than i/o" m diameter. Driven electrodes of pipes 
or rods, when of less than standard commercial length. 
shall preferably be of one piece and except where rock 
bottom is encountered, shall be driven to a depth of at 
least 8 feet regardless of size or number of electrodes used. 
Such pipes or rods shall have clean metal surfaces and 
shall not be covered with paint, enamel or other poorly 
conducting materials. Each electrode used shall be separated 
at least 6 feet from any other electrode, including those used 
for signal circuits, radio, lightning rods or any other purpose. 



GENERAL PURPOSE 
GROUND CLAMP 
FOR BARE WIRE 



ARMORED 

BARE GROUND 

WIRE 




Page Forty-five 



GROUNDING TO WATER PIPES 

The point of attachment of a grounding conductor to a 
water piping system shall be on the street side of the water 
meter, or on a cold water pipe of adequate current carrying 
capacity, as near as practicable to the water service entrance 
to the building or near the equipment to be grounded, and 
shall be accessible except by special permission. If the 
point of attachment is not on the street side of the water 
meter, the water piping system shall be made electrically 
continuous by bonding together all parts between the at- 
tachment and the pipe entrance which are liable to become 
disconnected, as at meters and service unions (See Drawing 
No. 54, page 45). 



GROUNDING TO GAS PIPES 

The point of attachment of a grounding conductor to gas 
piping shall always be on the street side of the gas meter, 
and shall be accessible except by special permission. An ex- 
ception to this requirement is given in a previous paragraph 
covering "Grounding of Fixtures." 

Means of Attachment : — The grounding conductor, in its at- 
tachment to equipment and electrodes, shall conform to the 
following: 

To Equipment. The grounding conductor shall be at- 
tached to circuits, conduits, cabinets, equipment, and the 
like, which are to be grounded, by means of suitable lugs. 
clamps, blocks or other approved means. 

To Electrode. The grounding conductor shall be attached 
to the grounding electrode by means of (1) an approved 
bolted clamp of cast bronze or brass or of plain or malleable 
cast iron to which the conductor is soldered or otherwise 
connected in an approved manner or (2) a pipe fitting, plug. 
or other approved device, screwed into the pipe or into the 
fitting, or (3) other equally substantial approved means. 
Not more than one conductor shall be connected to the 
grounding electrode by a single clamp or fitting unless the 
clamp or fitting is of a type approved for such use. 



GROUND CLAMPS 

Ground Clamps shall conform to the following: a. For the 
grounding conductor of an interior wiring system, the sheet- 
metal-strap type of ground clamp is not considered adequate 
unless it has a rigid metal base, seated on the water-pipe or 
other electrode, and the strap is of such material and dimen- 
sions that it is not liable to stretch during or after instal- 
lation. 

Protection. Ground clamps or other fittings, unless ap- 
proved for general use without protection shall be protected 
from ordinary mechanical injury (1) by being placed where 
they are not liable to be damaged or (2) by being enclosed 
in metal, wood or equivalent protective covering. 



SEPARATE CLAMP 

If the grounding electrode is also used for grounding light- 
ning rods, as for example in case of continuous metallic 
water pipe systems, the grounding connection shall be en- 
tirely independent of, and separated from, the lightning rod 
connection to the piping system. 

Page Forty-six 



COMMON CLAMP 

If two or more grounding conductors are used under a con- 
dition where a common grounding conductor is permissable, 
a common connection to the grounding electrode may be 
employed. In all other cases each grounding conductor shall 
have an independent connection to the grounding electrode. 

RONDING JUMPERS 

Bonding jumpers shall be installed as follows: 

Around Meters. Bonding Jumpers between grounding 
electrodes and around water meters, gas meters, unions, and 
the like, shall be of copper or other non-corrodible metal 
and shall be of sufficient size to have current carrying ca- 
pacity not less than is required for the corresponding 
grounding conductor. They shall be attached by the method 
as shown on drawing No. 54. 

In Cabinets. Bonding Jumpers in cabinets and the like shall 
be of copper wire or the equivalent and of such size as to 
have current-carrying capacity not less than is required for 
the corresponding grounding conductor. They shall be at- 
tached as shown in drawing No. 48, page 39. 

WATER METER SHUNT 

A water meter shunt may be made by placing one Ground 
Clamp on each side of water meter and running a copper 
wire of not smaller than the same size used for your service 
wires between the two clamps. Be sure that all connections 
are drawn up as tightly as possible and the clamps rigidly 
secured to water pipe (see drawing No. 54). 

TARLE "A" 



Size 

of 

Conductors 


Number of Conductors in One Conduit or Tubing 


1 


2 


3 


4 


5 


6 


7 8 


9 


Minimum Permissible Size 
of Conduit (Inches) 


14 
12 
10 
8 
6 
4 
2 
1 



V4 
*4 
Vi 
14 
14 
3 A 
3 A 
% 
1 


Vi 

3 A 
3 A 

1 

1*4 
Wa 
1*4 
1*4 


*4 

Vi 

3 A 

1 

Wa 
Wa 
1*4 
1*4 

2 


14 

3 /4 

3 /a 

1 

1*4 

1*4 

1*4 

2 

2 


3 /4 

3 A 
1 

Wa 
1*4 
2 
2 
2 
2*4 


3 /a 
1 
1 

Wa 
1*4 
2 
2 

2*4 
2*4 


3 /a 
1 

1*4 
1*4 
2 
2 

2V4 
2*4 
3 


1 

1 

1*4 

1*4 

2 

2 

214 

3 

3 


1 

1*4 

1*4 

1*4 

2 

2*4 

2*4 

3 

3 



The preceding tables are made up for your convenience. 
It is possible at a glance to tell exactly what size conduit 
is necessary to carry a given size and number of conductors. 
Table "B" will enable you, by the combined use of the 
formula shown at the bottom of this page and Table "B" 
to determine the size wire needed to carry a given load, a 
set distance and at a lire-determined voltage drop. 

The copper loss (i.e. energy loss due to resistance of the 
conductors) depends on the resistance of the wire and the 
square of the current which is carried. If appliances such 
as refrigerators, washers, irons, ironers, roasters, etc. are 
expected to operate at maximum efficiency and minimum 
operating cost, it is to your advantage to determine before 
you begin to wire, the exact size wire needed to carry the 
current to your appliances with the lowest possible voltage 
drop. 



TABLE "B 



JJW" 



Standard Sizes of Fuses, Enclosed Switches and Circuit Breakers 




for Lighting Circuits 






Conductor 






Conductor 


Size 


Circuit 


Fuses 


Switch 


Size 


(Circular 


Breaker 


(Amps.) 


(Amps.) 


(A.W.G. Ga.) 


Mils) 


(Amperes) 






14 


4,107 


15 


10-15 


30 


12 


6,530 


20 


20 


30 


10 


10,380 


25 


25 


30 


8 


/ 16,510 


25 


30 


30 


(16,510 


35 


35 


60 


6 


26,250 


50 


45-50 


60 


4 


I A 1,740 


50 


60 


60 


(41,740 


70 


70 


100 


2 


66,370 


90 


90 


100 


1 


83,690 


100 


100 


100 





1 05,500 


125 


125 


200 



The method used to determine the size needed to carry a 
given load a given distance at a minimum voltage loss 
shall be as follows: Determine the distance the wire will 
have to run, then multiply by 2. In the case of a 3 wire 



115-230 volt service, the same rule shall apply. This sum 
shall then be multiplied by the factor 10.79 which is the 
approximate resistance to the flow of current of 1 mil-foot 
of copper wire regardless of the size of the wire. This 
second total is then multiplied by the amperage needed at 
the outlet where the work is to be done. Your third total will 
be divided by the voltage loss permissible on this par- 
ticular installation (on an alternating current of 115 volts 
a voltage loss of from 3 to 5 volts is usually permitted). 
After the division has been completed the result will be 
the circular mil size of the wire needed to efficiently carry 
the current. 

By checking with the circular mil column of Table "B" 
the result of your figures will show the circular mil size 
of the wire needed. In the event the circular mil size ob- 
tained by your calculation is greater than that shown by 
the chart for any particular size of wire, the next higher 
figure shall be used. A Circular mil is the area of a circle 
1/1000 inch in diameter. One circular mil-foot of wire is 
a wire 1/1000 inch in diameter and one foot long. 

Example: A line is to be 200 feet long one way and 
must supply 20 amperes with not more than 5 volts loss, 
with a reading of 110 volts at }>oint of starting run. 200 x 
2 x 10.79 x 20 amperes = 86320 -=- 5 volts drop =17264 
circular mils. By comparison with table "B," it is found 
that 17264 circular mils is greater than the circular mil 
size of No. 8 wire, and since voltage drop must not be 
greater than 5 volts, we must use No. 6 wire. 



W 



Page Forty-seven 



It Costs Very Little To Operate 
Sears Electrical Appliances 



To show how little electricity costs for the most commonly 
used appliances on farms and in homes, this table shows 
the horsepower (where motor is used) and watt consump- 
tion per hour of use. *Electric current cost is based on a 
rate of 1c per kilowatt hour. For example: The wattage of 
the iron is 700. There are 1000 watts in a kilowatt. So we 
divide 700 by 1000 to get the kilowatt hour consumption- — 
.70 kilowatts. This multiplied by cost per kilowatt hour 
(4c) gives an hourly cost of operating an electric iron of 
about 3c. If your rate is more or less, see chart at right 
which shows how to figure costs at rates from lc to 20c 
per' kilowatt hour. 



Appliance 



I ron 

Sewing Machine. . 
Washing Machine 

Pump 

Fan 

Milking Machine, 

Heating Pad 

Range 

Refrigerator 

Vacuum Cleaner. . 

Grinder. . 

20-25 Watt Lamps 

Separator 

Churn 

Toaster 

Radio 

Incubator 



Size 

of 

Motor 

HP. 



l 4 






Watt 
Consump- 
tion Per 
Hour 



700 

40 
340 
340 

40 
900 

60 
1500 
200 
250 
550 
500 
340 
200 
450 

50 
120 



Avg. Cost 
to Oper- 
ate Per 
Hour 



$0,028 
.0016 
.0136 
.0136 
.0016 
.036 
.0024 
.06 
.008 
.01 

.0220 
.02 
.0136 
.008 
.018 
.002 
.0048 



Isn't that startling? Can you imagine ironing a full hour at 
a cost of less than 3c? Less than 9c weekly for the average 
family ironing. About $-l«.50 a year. Contrast the pleasure 
of ironing with an automatic electric iron that is always the 
right temperature with the old sadiron which must be re- 
heated often. Or with a gasoline iron that is heavy, must be 
refueled, lit and cleaned. No comparison in comfort, con- 
venience or in the quality of the ironing. 

The cost of operating a vacuum cleaner is about l/ic a 
day. Will a broom or carpet sweeper clean your rugs one- 
half as well-, or as quickly? $1.50 a month during hot sum- 
mer months to operate a big 6 cubic foot Coldspot Refrig- 



erator. Could you buy ice for that amount? Can you afford 
to pump 1,000 gallons of water every day for 3c, or 300,000 
gallons of water yearly for $13.00? That's the average 
amount of water to care for the home, 5 horses, 40 steers, 
8 milking cows, 300 chickens and 80 hogs. 

The chart below shows how to ascertain the hourly cost 
of operating any appliance at rates from lc to 20c per 

kilowatt-hour. 

















CHART TO DETERMINE 










COST OF OPERATION OF 










ELECTRIC APPLIANCES / 






900 ~: 










: 




*/ 






800 -; 














3d 

4* J- 






700 -: 














sf 


tz 








1 3c 


w 








^ /$ 


O 








'/# 


X 




600- 


2 
< 


r/fi 


2 






ex 

< 


7$ 







500 - 


CO 


*>/$ 









: q 


/i-> 









- w 

: 5 


w 







400" 


: 2 

- 




•s, 
U4 






- "7, 

: t- 


/&/<? 


■J 






- t- 


so* 








< 




K 




300 - 


: 2 




O 










O 








/ HOW TO USE THIS CHART 






200" 










100" 


~z / 








- 











r" 3(f 



5>< 



10^* 

The above chart was prepared by Prof. Frank D. Paine for the Iowa Engineering 
Experiment Station, Iowa State College, Ames, Iowa. It is published as a supple- 
ment to Rural Electric Report No. 6, 



*This will vary. 
company. 



Obtain average current cost from your power 



Page Forty-eight 



Sears, Roebuck and Company's Five Point Service is designed to 
assist you as far as possible in the installation of an electrical 
wiring system. 

Point One: Free Estimating Service. Sears will send you a free 
estimating blank, No. 6238L, which you will fill in according to 
instructions shown on the blank and return to us. From your filled-in 
estimating blank, we will make up a complete, adequate list of the 
materials you will need t6 do your wiring job. 

Point Two: Free Wiring Chart which gives simplified instructions 
on how to wire easily and quickly. This wiring chart may be ob- 
tained by ordering it under the number 9772 1L. 
Point Three: "House Wiring Made Easy," the book which you now 
have in your hands has been designed to assist you in the wiring 
of your home. 

Point Four: Sears will lend you the tools. We will lend you all the 
necessary tools to do the complete wiring job which you may obtain 
by simply sending a deposit as shown in our current catalog with 
your order to cover cost of tools. When you return the tools we 
will return your deposit. 

Point Five: Sears Easy Payment which permits you to obtain all your 
necessary wiring materials and pay for it in simple easy installments. 
If you have never bought electrical supplies, you may not know 
what it means when we say that Sears Electrical Supplies are Listed 
as Standard by Underwriters. 

Underwriters' Laboratory is maintained by the National Board of 
Fire Underwriters. Its object is to determine by reasonable, practical 
and independent investigation the relations of devices, systems and 
materials to life, fire and collision hazards and theft and accident. 
Its comprehensive testing equipment, its large staff of technical ex- 
perts, its constant checking up of materials and methods, and the 
practical information which these tests reveal have resulted in wide 
recognition of its standards and recommendations. Supplies which 
meet these tests are accepted as standard by Underwriters. This is 
your assurance of getting quality material. 

Sears wiring materials, appliances and devices ordinarily 
tested by Underwriters 1 Laboratory are listed by it. 
The Rural Electrification Administration also requires that Under- 
writers' Approved materials be used in this great program. 



F-5428 



*